Welcome back to Allods Online! I definitely think you should give it a a go. You'll probably otherwise just keep getting nostalgia trips back to this game.
If you don't like it, then at least you gave it a try and you probably won't feel like trying out the game again for at least another year or so, then nostalgia might hit you again
At least this is what usually happens to me.
I was in your situation not so long ago, however I couldn't decide if I should try the P2P server or go back to the F2P server where I already spent quite some time and money. I decided to go for P2P however, and to be honest I didn't enjoy it at all. I'm usually ok with a low population, but this was way too low for an MMO. An MMO is not supposed to be played as a single player game. That's what it felt like though during the whole leveling process. Since leveling to 75 in this game takes quite a while, I just couldn't reach max level before I got bored to death and completely lost interest.
I ended up leaving the game aside once again. It was just a few days ago that I decided to try out the FP2 server again, and now I'm stuck
I don't really like the Summoner anymore since 8.0 patch though, so I hope that I'll find someone who maybe wants to level up a reinc with me eventually.
P.S. I'm not trying to convince you to play on F2P server, that's not the purpose of this post, if you're played the P2P server before, I think that's the one you should try out again! Since the low population doesn't seem to be problem in your case, it's all good