As a pax I love the ERJ145 - that single seat is great and certainly gives you more room than having John Candy (RIP) sat in the seat next to you on a mainline airliner. Other aircraft that employ 2-2 seating however certainly aren't as comfortable as the ERJ145. I've started flying quite a lot in the states recently and flying with CO
I would choose the ERJ145 over the 735 any day of the week.
The Dash 8 on the other hand (whilst not a jet) is awful from a pax perspective and I aviod it where I can. I'll take a bet though that FAs hate RJs more!