I believe there is an update or free DLC that is coming out down the line called "Tournament Mode" or something silly. Apparently that mode will disable gems in future play. I was like you Raden for a long time in that I was going to pass on this gmae, simply for the fact that they implemented this gem system and then bring out DLC gems. The basis of gems didn't seem to bad, it was just when they tried to bloody start selling the damn things instead of just giving us them all that really swayed me away. How can you say the gem system is critical to gameplay and then try and sell them on additional? It peeved me off for a long time, but I've calmed down a bit now and I've been keeping an eye on the game for the last two months.
My friend (game's tester) who has managed to play the game said the gems are barely a game changer within fights, (though I bet he didn't get a chance to use auto block and throw escaping gems) and that the game is very fun. I'll be getting this game, mostly because Soulcalibur 5 just looks so disapointing for someone like me, and the two player aspect of this game is something I've looked forwards to for a long time. I'll get this game, but I won't invest any money in gems beyond buying the stand alone game.
If there is one thing that gets me though since this gem system came out, its how the developers keep contradicting themselves with each interview. I recall the purpose of gems according to them at one point was to even the playing field with old school expert players and newer guys, helping the newer guys to get into the game with these gems. Sounds very bogus when better players also have access to said gems, making them potentially just more powerful then before. They then turn around and say these gems won't actually help a new player defeat a more skilled player, that is it more like equipment for your fighters to customize them. Which makes me wonder what the hell is the point the gems? Customization to me is having a unique looking fighter, not a gem that makes him turn red with a slight attack boost for a few seconds. They keep changing their story on these gems too much for me to take them seriously. So these additional gems will be avoided by me, along with ranked matches online. (I'll try and find rooms with no gem rules and make friends with peeps who don't use em for online games.)