I currently use the FG5000 and have tried on a FG2900. I didn't get the chance to use the FG2900 since I was recovering from injuries, but I tried it on and noticed it's not the best at stopping nose strikes. If you can, get the FG5000 (ebay might take a while so buying from Winning might be better) and sell the FG2900 on ebay. The nose protection is amazing and hits are absorbed well. There isn't much chin protection and one of my boxing coaches at the UFC Gym thought my headgear was too small. I rarely get hit in the chin anyway and it's not really too much of a problem.
I haven't tried a Cleto Reyes yet, but if you do get that, make sure you know which model you are getting.