I've never tried these Vanilla servers, mainly because I'm always a bit scared that my time invested will end up being fucked over by Blizzard. But I really do understand why they are so popular, and feel for your loss. If only Blizz would lay off this shit.
The only time I really enjoyed PVP was in Vanilla. Both before AV, when you had those epic fights in Southshore, and the hours long AV fights. I remember taking part in one one evening. That had been going on for hours before I joined. I spent a good time there and raked up many kills. Then I logged off and went to bed. Woke up the following morning, logged in, and lo and behold, ended up in the same AV fight as the night before.
Some people may not understand what was so fun about taking part in something you wouldn't "win", but for me, and I think many others, "winning" an AV battle was not the fun part. The fun part was the endless, target rich environment, and the eb and flow of the battle. Damn I miss that.
I also miss the epic scale of getting from 1 to 60. It was an adventure in itself back then, not just a means to an end. The main problem with WoW now is that if you're not max level then you're fucking "missing out". But back then you could do so much more on the way.
/nostalgia :'(