I can't be certain of the percentage, but I'd say it's well into the 99+ percentile range of me using a condom.
Well, like in many things, going against the grain of what "most people do" has been pretty beneficial for me. No pregnancies, and only a couple morning after pill situations where the condom had broken or slipped off (marathon session without replacing it when it finally got a little slippery), that probably wouldn't have resulted in pregnancies anyway.
All the girls I've fucked have been on some sort of birth control (that I've known) and I still always grab a condom. I'd way rather be safer than sorry. I'm not sure, but I suspect that a lot of guys are using shitty fucking condoms or they've had a circumcision and therefore don't have that much sensitivity so once they put a condom on it's a really poor experience.
Plenty of times I've fucked with the condoms I buy in bulk and have been completely in disbelief that the condom is still on because it feels that damn good (yes I've felt raw when a condom broke or slipped off, it IS better but not by that much that I would care vs. leaving the opportunity there for a pregnancy). I don't work for this place nor get any benefit from them, but Condom Depot has been fucking awesome (pun intended) to me. I am now up to buying condoms in a 100 pack at a time (I think the last time was close to 20 cents a condom landed cost) so I always make sure my overnight bag, pants (when I go out and I'm not near home), and nightstand drawer always have condoms. Hell, I give them to my friends in fistfuls just to see them not fuck up.
Here's the link to the condoms I buy on Condom Depot. The small portion of the porn industry that DOES use condoms use these. They're phenomenal imo, better than any other "thin" condom (or any condom for that matter) that I've tried.
The same company also makes the 004 condom which is supposed to be the thinnest condom on the market. I haven't tried them only because I've been very happy with the Crowns and the 004s are priced significantly higher.
Guys, do yourselves a favor and spend a few dollars up front to have the peace of mind and ease of access to condoms at all times. I consider this to be the same as going to the grocery store and buying a bunch of healthy food so that it's around and it's easier for me to make good decisions...and I ALWAYS feel better afterwards having made the right decision. An easy way to cheat the difficult part of making good decision is setting up the circumstances to encourage it.