As good as Virtua Fighter 4: Evolution. Fighting games don't age like other games. More realistic than Tekken 6 or SCIV
That being said, this game fell a little bit short of my expectations. This is going to sound very strange, but the graphics are both better and worse than Virtua Fighter 4. They're better in the sense that the game is hi-res, fits my widescreen LCD, and is more detailed. However, as they say, the devil is in the details; it seems that the game has lost of visual quality and finesse when it was reworked for the new graphical format. A lot of the character models look worse and in many instances cheesy. The rings and backdrop are gorgeous, but they too seem to have suffered aesthetically. It really seems like the developers tried to "overdo" the graphics and ended up creating a game that looks worse than VF4; it is a little more flashy (or dare I say gaudy) and a little less realistic. Some people will like this. In any case, play them both and you will see what I'm talking about.
As for the content, I have mixed feelings about the new characters. I think Eileen is great and totally worth her weight in the game (she probably doesn't weigh that much, though), but "El Blaze" is one of the most retarded things ever to be found in the entire series. Having a lucha libre character is actually a decent idea, and the end result could have been very nice, but for some reason it just didn't work out here. Every time El Blaze appears in the game, you will cringe. I also thought that Brad and the blue guy were stupid characters when they were introduced, but even they are better than El Blaze. In fact, Brad actually seems better in VF5 than he did in Virtua Fighter 4: Evolution. If you ask me, the creators of VF are doing a poor job attempting to integrate more "Western" style fighters; many of these recent additions are bland and uninteresting, and they probably don't correspond very well to actual martial arts trends in the Western world (not to say that the game is supposed to be realistic, but it does have better realism than practically all other fighters).
Which reminds me--if you've never played the VF series before and are just looking for a fighting game, you might appreciate the game's relative amount of realism.
This game appears to include all of the great features that were introduced in VF4:Evolution. You can skip the monotonous Arcade mode and go for the Quest mode, which lets you fight more varied opponents for rank and prizes such as character customizations. Unfortunately, I daresay that VF4:E does these better than VF5 does.
Overall it's a great buy and a solid PS3 title to keep on your shelf. I'm still convinced that Virtua Fighter is the best fighting game on any platform (sorry, Soul Calibur), so if you want a fighting game for the PS3, this is it (Tekken fans, prepare to launch your rebuttal).
IF you have a PS2, then get Virtua Fighter 4: Evolution instead; you'll save some money, and I honestly believe it is a better game than VF5 and possibly the best fighting game I've ever played. It's fair to say that VF5 is just VF4:Evolution with updated graphics (and alas, if only they had just done that!). If you are playing on an HD display (eg widescreen LCD), then definitely choose VF5.