As someone who has lived in the Calgary for a little over a year, after spending time in several other Canadian cities, my short answer would be this:
1) It's okay to live in, not that great or livable compared to most other big Canadian cities.
2) Everyone else who lives here will tell you it's great.
It's unbelievable the amount of misplaced pride people have in this place, relative to other places in Canada. This belief that "Calgary is the promised land!" is more pathological than Winnipeg's hopeless inferiority complex ("Hey! Look at us; we're still here!"), or Montreal's insistence that everyone has a great quality of life despite perenially depressing economic figures ("You english just don't understand."). I think this complex stems from the fact that so many people are desperate to justify the fact that they moved here (for work) from nicer, more livable places, twinned with the fact that, as the "next Toronto", economically speaking, they can feel the growing resentment from the rest of our complicated land...
More in depth...
Calgary is in a beautiful geographical area; there's no doubt about that. It's wonderful living so close to the mountains, but the endless prairie on the other side of town is gorgeous too. In the middle, there are all kinds of great little lakes and valleys in the foothills. Lots of opportunity for good hikes, although my favourite sport of cycling has really taken a hit - most of the mountainous areas nearby don't allow biking, and it's way too windy to ride much on the open roads.
The airport is easily accessible, with a steadily growing flight offering. As I recall you're from the midwest somewhere; should be easy one-stop trips home, and relatively convenient to most of the western half of this continent.
The people here are generally decent; I won't begrudge them that. The conservative politics don't really suit me, but that's democracy for you and I don't mind being in the minority as long as people's rights are still respected. As an American, you won't find anywhere in Canada more politically like home (including low taxes) than Calgary. You shouldn't have trouble finding a church you like, either. There is a growing diversity here, too, which is slowly making things interesting. Immigrant populations are increasing, and Calgary recently shocked Canada by electing a South Asian, muslim, *ahem* 'confirmed bachelor' as mayor. Interesting times.
Another big pro is the University of Calgary itself. I haven't attended there, but my fiancée does, and though it was once the poor little sister of the U of A, I get the impression there are lots of good things going on there. The campus is vibrant and dense - in a way that urban planners should have taken note of for the rest of the city. It's obviously close to the Foothills and Children's hospitals (which I imagine would be of interest to you), and it's on the C-Train.
The C-train is another plus. Given the fiscally conservative nature of politics here, we're lucky to have such a good light rail system. It's not extensive enough, but if you strategically locate yourself it is a good system.
The biggest plus, I guess, is the generally steady and growing economy, which I guess is what has brought most people to Calgary to begin with, and what makes them stay. On the other hand this is irrelevant to you as a student/researcher, and also to myself who has a government job that would pay the same no matter where I was, meaning there's no advantage to being in a 'boom' area. Perhaps if I had come here to make 'big bucks', I would have an overall rosier view of things!
Calgary doesn't have nearly the cultural scene that one might hope. Compared to many cities of even much smaller size, there is a dearth of really walkable areas, individual restaurants, nice cafés, etc. It compares very unfavourably with ANY of the large Canadian cities it's size (except maybe Edmonton), and several that are much smaller. Drive south to Missoula, MT
, and you will see a city with more to enjoy than Calgary at only 5% it's size. God help you, my friend, if you are forced to compare it to London!
After we moved here, we kept looking for the 'nice part of town', particularly downtown, and gradually realized that it doesn't exist. Note that I don't mean that the town is 'run down'; it's clean and safe (excellent police service) and has all the necessities, etc. I just mean that there aren't a lot of nice places to 'hang out'. Kensington is great, but it's tiny and really only amounts to a handful of nice joints. 17th Ave. S. is nice too, but a little more spread out and again not that big. There's also a minute number of nice little places in Bridgeland. But all these places are far apart from each other. And in between, the classic 'downtown' of Calgary, where the big buildings are, offers little draw for anyone who isn't, well, working in those big buildings. There's one nice underground mall, and there is a top-class theatre/concert venue, as well as a nice littler theatre, too. But when the show's over, you just go somewhere else... Most will go to the endless suburban strip malls for a meal, leaving little life in the real city. Kensington and 17th can only go so far, and this aspect has been a real bitter disappointment in our move to this supposedly 'hot' city.
There doesn't seem to be any end in sight to the above, in terms of urbanm revitalization. The sprawl that Calgary is making is horrendous - not in the number of new homes (no problem with that), but in the pointlessly wide waves of development, with neighbourhoods that are completely unwalkable in their scope and layout, and are placed endlessly further away from any real centre. This aspect is not as important to a student, but good luck to anyone wanting to raise a family in this sprawl who will have anything but a cookie-cutter existence.
In summary, despite the above bitterness, I wouldn't dissuade you from coming to Calgary. Like I said, the people are decent and that might be the most important thing for enjoying a few years here. The school is a cool place and there are lots of things to do nearby (particularly in the mountains). Just don't expect much life from the city itself (other than Stampede week!). For all the hype, it's really my opinion that at the moment, Economic Emperor Calgary has no clothes.
A couple of practical points you touched on:
Doing a post-doc should, I think , quailfy you for a student visa which should be no problem at all for an American. Check with the university, but I wouldn't anticipate any trouble here. As a student in Canada, you probably won't need to re-register your car and they won't want you to get an Alberta licence. You can stay nice and American; I actually see a lot of California plates here. You may want to check whether the university has a good health plan to offer you during your post-doc, in order to be covered as you partake in the long but free waiting lines of the Canadian health care system.
As far as rent goes, do keep in mind that the market here is the weakest it has been in quite some time. This means that there is a good chance that rents may have risen quite a bit by the time you leave, although perhaps not to SF
levels. So you may want to budget a little more.
If you're at all in a position to buy a small condo, it might be a smart investment for when the market inevitably rebounds.
Good luck with your decision, and I'm sure you won't regret it if you do come here. Just don't buy the hype that it's one of the greatest places in Canada to live!
[Edited 2011-03-24 01:26:21]