My major concern at first was that these power ups would totally unbalance the game, but with time you realise that the ball will eventually arrive where you expect it, and the patterns can be learnt with time. The only way the special moves will annoy you is that certain characters can summon obstacles or hostile characters that will appear on your side of the court, which can be infuriating when they knock you down or block your path to the ball. You may end up hating matches with the Jet Set Radio crew or Space Channel 5's Ulala for exactly this reason.
Now we come to the crunch. If you're simply looking for a great tennis game there's no doubt that Virtua Tennis 3 is still the better choice. It has the longer and deeper career mode, more sophisticated AI, more immediately impressive graphics and plays a slightly tighter game overall. What makes Sega Superstars Tennis special is a) that it has more kiddie appeal for those of us with families and b) that you can unlock such obscure Sega stars as Ulala or Alex Kidd if you're a Sega nut. Heck, I'd prefer to play VT3 myself, but I'm not a pre-teen or a fully signed-up member of the Blue, Blue Sky brigade. All the same, I should note one word of warning. While anyone who has sunk hours into VT3 will find Sega Superstars Tennis a mite too easy, other players - particularly younger ones - will find it very challenging at times. I'm not sure how many people will sit in the middle ground in-between. All I'd say is that I've yet to come up against anything that couldn't be beaten with a little hard work, and I'm certainly no Virtua Tennis god.
Those of you with both an Xbox 360 or PS3 and a Wii will also have a difficult decision to make. On the one hand, the cartoon graphics on the high-end consoles are clearly more impressive, not just thanks to the usual HD crispness, but also because extra lighting and surface effects and background details make the experience that much richer. You might not think it would affect a cutesy cartoon game, but look at the all the activity in the background of the Samba di Amigo levels and you'll be surprised what you'll see in the 360 game. On the other hand, the 360 version suffers from some painful loading times (I haven't seen the PS3 version, though I'd bet it's not much different).