I stopped playing around the time golden wrenches were added. I hated the way the soldier medals were awarded and the golden wrenches were even worse (to the point someone gamed the system to get him and his friends several, and ended up getting a VAC ban).
The class updates I liked, although they didn't update as often as I would have liked, but the more and more items they kept adding just ruined it for me, especialy items that can only be obtained for limited times/purchasing other games/buying the items for real money.
Was a great game at one point, but the TF2 devs have lost their way IMO. It has changed too much from playing to have a bit of fun to a 'gotta catch em all' game where half the players care more about getting silly items than playing the game, and for those who just want to play for fun it has just gotten repetative for me as the devs do no work as they let the community make all the items and just add them into the game instead of making real development to TF2.