CEE has been out for a while now so there's feedback. The new ethyl esters like arginine and glutamine ethyl ester haven't been around that long, so feedback is lacking. Best to do a search across multiple sites to pull as much as you can. I haven't seen either mentioned here at all, except in conjunction with discussion of ALRI's N'Gorge, which contains the glutamine ethyl ester. Most feedback on that product has been good.