Where did you find those videos?

Youtube.

http://www.youtube.com/watch?v=j0fuPzbBpNQ

http://www.youtube.com/watch?v=CXRhDrjv_Ok

The second video doesn't show the player, so it's not possible to tell lag from that one.

The first video shows that it isn't exactly 1:1 but I'm not sure there's lag. Sometimes he moves earlier than he needs to, but the game gives some tolerance in timing I guess?

I offered my initial impressions on GST a couple of days ago on this thread.

http://www.vgchartz.com/forum/thread.php?id=76090

Having played the game for many, many hours now, i can say that it is really a fun game though the AI and the controls can get a little frustrating at times.

One major plus point about GST (not mentioned in the thread due to absence of online players) is that online is pretty much seamless with no lag whatsoever, and oh my god it is fun. Firstly, its a nice break from the inconsistent AI. Even losing a rally can be fun, as its nice to know that your opponents incredible shot is really being performed by some other sucker in his living room trying to figure out the complex controls.

What has shocked me though, and has inspired me to keep practicing, is how incredibly good some of the online opponents are. Sometimes i wonder if its just computer AI, because, apparently it is possible to be amazing at this game. I had me butt served to me on a tray so badly a couple of times, i had to quit online and start practicing again. And trust me, you will need practice, because these controls are definitely not as intuitive as Wii Sports Tennis. But when you get it right, it is possible to do so much more, and be infinitely more satisfying.

This is very true. And this has actually made me consider buying the game again.

Finally, here is a review from someone (who plays tennis) and owes both games (from Amazon)

I've had Grand Slam Tennis and Virtua Tennis for one day and played them about 3 hours each. I've played tennis for years. I'm using Motion Plus.

Here's a comparison.

Tournament mode: Grand Slam wins by a kilometer --- In Grand Slam Tennis you play the Grand Slam tour and do some exhibitions. No stupid "shopping races" like in Virtua Tennis. This part of Virtua Tennis is highly annoying. I don't want to run around a court on a shopping spree and jump through arbitrary hoops in order to play in a tournament. This part of Virtua was so annoying it took Virtua from 5 stars to 4 stars for me. Grand Slam exhibitions / mini games are fun while Virtua is annoying. On the other hand, you can just press "play" and choose tournament in Virtua but the experience is not as full as Grand Slam.

Graphics: Virtua Tennis wins by a meter. The crowd is better and players movement's are much more realistic to the player's style. Grand Slam's graphics are more cartoonish but with the announcers and the angles and replays it is more like participating in a match while you watch it on television... the presentation is better but does not make up for the better Virtua movement and detail.

Speed of play: Virtua Tennis by a kilometer. Your character moves at a more realistic pace and the match is just a more entertaining, fast action pace.

Controls: Grand Slam by a centimeter: Grand Slam's controls are easier to master. Virtua's controls have less tolerance for error. You MUST complete the training coach with Virtua to master any advanced shots, even then the drop shot leaves me wanting to smash the controller! Grand Slam's topspin, backspin, and fade are more true to real tennis, while Virtua's serve, lob, and dropshot are much more true. Grand Slam allows you to "cheat" somewhat by using the nunchuck to help with your crosscourt winner, while Virtua requires you to nail it perfectly. While I appreciate Virtua's effort, sometimes my intentions do not translate, but I suppose that's true in real tennis too.

Overall experience: A tie. Really. I appreciate Virtua's pace and effort at control realism, but Grand Slam gets the top spin and back spin nearly perfect... and that's a huge part of a real tennis player's game. Grand slam lets you cheat using the A button for a lob and B for a drop shot, and the nunchuck for crosscourt slams. Virtua has great realistic smash and lob controls, but the drop shot is just too hard and overambitious. The tennis stars in Virtua are more current and broader. Grand Slam gives you classic stars and current stars. Virtua's graphics are killer but the career mode is like throwing Jar Jar Binks into Star Wars... annoying and distracting. I want to play tennis, not the Sims! They both have room for improvement, but for a quality virtual tennis experience both beat the "plug and play" Wii Sports. Both require a bit of patience to learn. I'll come back to both for different reasons. 4/5 stars for both!



LOL - Unfortunate it doesn't help us decide which to get...

Wow read all that and still don't know which one to get.  Super annoying.

@tuoyo: Do you want to play online? If you do, that makes the decision pretty simple from what I've seen, and the winner would be GST.

LOL - I know!!  But it's starting to look like this - Both give a great but not perfect 1:1 tennis gameplay experience.  Both have there own idiocentricies.  Virtua has better/more realistic graphics, Grand Slam has better overall presentation.  Virtua's tennis gameplay is quicker but harder to master (?)  Virtua is $10 - $15 cheaper than Grand Slam but Grand Slam's online is superior and seemingly infinitately more enjoyable.

So I think if you're not going to play online (much) Virtua is a better deal, but if you want serious online competition Grand Slam trumps.

@Gamerace: In Europe, I think Grand Slam Tennis ends up being cheaper than VT when bought with WM+.