I have noticed there is a huge difference in condom quality and my ability to feel when I’m having sex (when I can have it). I’ve also noticed that the same brand and style of condom vary greatly from country to country so even if the packaging is the same the condom may not be.
Two things that I noticed about standard latex (both Trojan and Durex ranges from normal to sensitive to studded) is that they are too tight. When I do get erections and put them on they are literally so tight they squeeze the blood out. This, in combination with the lack of feeling with latex, kill my erection.
Two condoms that have been working are the Trojan Magnum (not nearly as tight, maybe I should have been using them all along) and Durex Avanti. The Magnums are bigger than standard latex so they don’t feel like I’ve triple-wrapped a rubber band around my erection. This is nicer however there is still a bit of a problem with lack of feeling. The Avanti condoms are made from a new material that actually feels closer to natural skin. These, even though they are a bit tighter than the Magnum, are nice because they let quite a bit of feeling through. My girlfriend really likes the Avanti too. Actually, through using the Avanti, we found that she was allergic to latex in the first place, and it was making her dry quickly. The different material of the Avanti doesn’t cause this.
If you’re having problems with keeping the erections do a bit of condom research. These two are working for me now (primarily the Avanti however my supply is limited until I’m back in the US).