well... I have downloaded and installed, and played around with it and I see no Gofriller cello, or Strad violin in there.... GPO 5 has the same strings as GPO 4 with the addition of the GOS set... that's it. There may be some new strings added, but I am not sure because I don't own the original GOS set. There are some new instruments that sound pretty great, all the old ones seem to have been reworked, and do sound better, more up front with better loops. The staccato at the top velocity seems much better and not so fake. The new pianos, harps, and organs sound pretty great, I really like the pianos. There is some new percussion stuff and the convolution reverb seems improved with more IR's. The ARIA player has some new features such as mic choices such as x-y, stereo pair, etc. All in all, it does sound much better than GPO 4 and for $49.95 upgrade, 52.00 and some change with tax, I think it was worth it.