Yes, it was quite the "coincidence" that the GSi one got updated to 64bit (on windows anyway) just a few weeks back after many years of lying dormant. Now don't get me wrong, I liked the GSi plugin a lot, it was just about the only Space Echo plugin (other than UAD) you could get and in all fairness, it sounded really good.
But... Outer Verb is just the better plugin, period. It sounds great, has a much more usable UI, has temp sync, controllable noise, over-sampling, yada yada yada. As good as GSi is, and it is good, Outer Verb is better. More expensive yes, but not outrageously (β¬39 vs β¬19). I don't see myself every firing up GSi again now I have Outer Verb.