Uniform sets vs varying weight?

My training has always involved doing a few sets of each excercise using the same weight on each set, however I have noticed a lot of people who train by starting off at a lower weight and then increase to a higher intensity by their last set. Which method works better for you all?

I usually only do set weight through all sets on assist exercises. For bigger lifts I like progressive loads.

5'6" 125/ Bench: 115 / Front squat: 90 / Deadlift: 205 / Pullups: 10

i actually just had a long thread at t-nation about this with a few people. a lot of them felt that it would be better to do ramping sets for an exercise to 1-2 max sets (maybe 1 hard, 1 complete max of the given rep range) than to do 3 sets of the same weight.

this is it if your interested, http://www.t-nation.com/tmagnum/readTopic.do?id=2288223&pageNo=0

it starts off just talking about progression but in the 3rd/4th pages it talks about exactly what you mentioned

It's called ramping sets and static sets, btw. If you're doing a proper warm up, you should already be ramping the weight up to your working sets, so I just use the same amount of weight for my working sets.