Lol, this is a funny thread. I'd like to contribute. Agree with Christmas, the Okamoto 002 is awesome. Heat transfer is phenomenal due to the extreme thinness of the condom. However, it is unlubricated so can be a bit dry!
The sagami 002, on the other hand, is lubricated and has the same thinness, plus the packaging is much easier to use than the okamoto. So I like that one better.
About the relatively small size of these jap condoms, I fit the standard Aussie sizes (I'm about 7 inches erect, bone pressed) and even I don't have a problem putting the jap ones on. They are tight, but I think that's part of the design to fully enjoy the thinness of the condom. The thing to remember when using them is you need to be really hard when putting them on. The material used is not as stretchy as rubber so if you're not hard enough, the condom can literally squeeze the life out of your erection!