I get that it's the general impression of EPO because endurance athletes do get popped for it frequently - so it is understandable why people would think it helps with the aerobic/endurance side; but in reality its benefits are in the "burst" and "speed work" aspects of racing ie. Hill climbs and overtakes - this is why it benifits sprinters. Famously EPO was a significant part of Tim Montgomery & Marion Jones doping program. For the endurance work side cortico-steroids to reduce inflammation are often benificial.
As for experience in what is used; from what I've read on here the UK T&F (where I am) and US scenes are quite different in terms of PED use. Certainly in the circles I mix in EPO is not commonly used (probably because it's hard to procure; atleast at amateur level). Stimulants aren't overly popular although I know a handful of Tri guys who hammer amphetamine like it's going out of sale
medium ester test, EQ, low dose anadrol and var are all very popular here. Winnie is typically shyed away from - in the last year NPP has become very popular too.
Edit: oh and GH. we all love our GH