There is another thread about La Paz started by yourself: http://www.airliners.net/discussions/general_aviation/read.main/941084/
This is my part:
I visit LPB about four times a year. Most of the time I take the AA922 flight from Miami nonstop to La Paz. AA
Uses a 757 for this 6 hour flight. Many Bolivians use this flight to shop during the weekend in Miami. The plane is most of the time fully packed with people and unbelievable quantities of hand luggage. I've seen people trying to check in a huge fridge (which was refused btw). So, it doesn't seem that AA
is using weight restrictions for the inbound leg of this flight. The outbound leg has a stopover in Santa Cruz. This is only an hour away from La Paz so fuel levels can be low. As far as I know American is the only none south-America carrier which flies to LPB.
I also flew in on Varig from Rio de Janeiro via Sao Paulo and Santa Cruz. Varig uses an old 737-300 which is also often fully booked.
I had the oxygen masks coming down one time on a flight from Arica, Chile to LPB. The whole cabin was screaming from fear! Pretty scary.
You will see loads of 727's in LPB because LAB and AeroSur still fly these old birds on a daily basis. There are always a couple of 727's on the platform. I just love these old ladies in their faded blue and green liveries.
However, the best part of flying into LPB is the incredible beautiful view from the plane as you fly past the many mountains in that region. The sky is almost always crisp blue and during the take off roll you will fly past and below the top of the mountain Illimani which is over 6000 meters high at maybe a 1000 meters distance or so. So bring your camera on board and try to get a window seat on the left side of the plane.
Never be afraid of what you like. (Miles Davis)