I still play it off and on depending on how busy I am with other things whenever a new character drops twice a year. Sanyaa, despite being blatantly overpowered as shit, was easily one of the best feeling thief/assassin characters I've ever played in any video game. Didn't try out Neamhein because she just didn't look interesting to me.
As someone who put around 70 hours into the Defying Fate beta and has around 1k hours in OG Vindictus, I will say that the latter has significantly better feeling combat, at least to me. It's faster, more fluid, the hits feel better, the dodging and blocking feels better. There really is just nothing else like it.
It has a small community, since the game is fucking ancient, but I'd say it's also one of the most chill communities you'd be able to find these days. Pretty much everyone is a 30+ year old giga coomer that's only there to slap some bosses while staring at some tits and ass. I've never seen anyone get salty in a raid or anything. Pretty easy to make friends if you wanted to, something that's almost unheard of in other MMOs these days.
The game is pure slop for the first 20 or so hours because it's way too easy with the free gear they give you. Once you get to season 3 it becomes tolerable, and bosses don't just die in two hits anymore, but still not very good. If you manage to make it into season 4 (30-ish hours) you'll be rewarded with what I'd consider the best action RPG out there. The fun will last anywhere from a few weeks to a few months, at which point you'll hit a massive wall because the gear you need to do the final set of raids requires insane grinding. That's usually when I quit.

Overall I'd say it's worth a try. At first I thought DF was intended to replace the original but without some drastic changes I don't actually see that happening. Not only will DF likely not even have half as many characters, but the speed of the combat itself is also like, half as fast. More "Soulslike" instead of a zippy action RPG.