Do NOT upgrade to v7. I repeat DO NOT. Frankly there isn't much to warrant getting it. You can get the free EQIII and Dynamics III plugs that came out with later versions for free and I'm 99% sure they'll work in v6.4. I've also been experiencing problems with my MIDI control surface (motor mix) and Digidesign have verified it's a problem introduced in v7. I've since switched back to 6.9 and haven't really missed anything.
BUT, the real reason not to upgrade is Digi is releasing a bundle that includes 48 stereo tracks (as opposed to the 32 voices now), multi-track Beat Detective for LE, along with several other plugins and (drum roll please)... v7.1. That means if you want to get any of those things, you have to buy it in a bundle that will include an version upgrade, which means if you up to v7 now you are basically are wasting your money. Digi may decide later to release things in that bundle individually, but for now I would not do it.