Well, in a way, they are probably both right - when you play against a lot of fish, they tend to call you down with the worst of it, which inevitably leads to more bad beats.

For the more experienced player, you understand that bad beats are part of the game - especially when you're taking advatange of poor players (think of all the times they DIDN'T hit and you took their stacks!).

For the less experienced, a few bad beats strung together can drive you insane and make you think the site is rigged and totally sucks.

So, to recap PartyPoker-
Tons of bad beats - that can be partly true.
The easy to clear bonus is true.
Lots of fish is true.
Worst place - not true.
Best place - open to opinion.