I've tried the LTS's in all their versions, and I still am using the Main Edition of Gloria as my main OS. Gloria is much faster than Elissa, even compared to the lighter Xfce edition.
When Helena, or Mint 8, is released, you might dip your toe in by downloading or purchasing a CD and running it live, that is, by just restarting your computer with the CD in the drive. It will boot up in Helena without any change to your system, albeit much slower than it would be had it been installed. You probably know this, but there may be someone else reading who will be helped by this. It might tempt you to take a chance on it, or it may just satisfy your curiosity just to see it.
But I still feel you can't go wrong by sticking with Gloria.