I actually really LIKE Possession and Saboteur, as neither of these cards are strong cards as such, but both can change the way you have to look at a kingdom.
I'd agree about Tournament, however. It seems too luck based 90% of the time, even if there is some strategy in how you get the first province, etc. Followers with no other cursers is one half of it, but the other half is the annoyance of the blocking effect of an opponent's province-in-hand, which basically is something almost entirely luck based, and something you can do very little about.
Yes, there's definitely a skill factor in tournament (like manipulating deck density, working the draws, knowing when to duchy, etc.) but I still find the card too swingy for my tastes.