Being possibly the only person on here to be able to directly compare VF4 against Tekken 4, I would have to say that, currently, Tekken 4 is not being played, whereas VF4 is taking precedence over any other game I have. Admittedly, I haven't been playing VF4 for all that long, whereas I've nearly played Tekken 4 to death already, but that's not quite the point. It was nearly a no-starter, though. I played the game a couple of times (including the near 2-hours it takes to go through toe training with Kage), couldn't beat Akira at the end of the Arcade mode, and had come to the conclusion that the games was sh*t, and was about to never play it again. I decided to give it one more go, this time playing as Lei Fei, the Shaolin Monk. This time, I had somewhat more fun, seeing all the moves that I have seen the Shaolin Monks do on TV. I eventually beat Akira and won the Arcade mode, only to be rather dissapointed that that was it. No 'Congratulations, you've won', never mind any sort of story. I understand, of course, that this is just the VF way, but it's a little irritating after Tekken, which has quite a good story (for a fighting game...). I am currently enjoying the Kumite mode (on which I am 1st Kyu, since I am now fighting too many Dans, who are nigh-on impossible) and unlocking loads of neat stuff. My one major gripe with the game is that when you get to too high a difficulty of opponent, all they do is floater moves, which take off nearly half of your energy every time. This is more than a little irritating.
It remains to be seen whether it is better than Tekken. I'm going to have to play this for another couple of days, then play Tekken again, and then we'll see.
Summary: Great game, quite realistic in parts, nice backgrounds...snow and sand effects are nice. Kumite mode is great, A.I. trainer is fun, if quite confusing (I really can't see how to get the A.I. character to actually block, or move quickly)
Graphics: 10 (beautiful, simply stunning in places)
Sound: 8 (not quite the bone-crunching sounds of Tekken)
Gameplay: 9 (Starts off low and gets higher all the time. Until you start fighting computer characters that are and always will be better than you...)
Longevity: 9 (I've not even mastered ONE character yet...)