Dean:
I've used diapers for 5+ years and a few times have tried condom catheters (CC's) to see if they would work for me. Unfortunately no matter how meticulous I was in applying them I would sometimes get a "blowoff" where the CC would come entirely off and generally cause a huge leak. I even tried a Posey strap and medical tape to help keep them on and it did help a bit but I still had some leaks. I even tried wearing a pull-up over the CC but that made routing the tube difficult and would sometimes contribute to pulling on the catheter. I also found it difficult to route the tubing to a thigh bag without constantly getting a kink in the tube or catheter tip which would then lead to a significant leak or blowoff. A leg bag worn on the calf did work better but wasn't really an option as I wear shorts most of the year here in Florida.
The only real positives I could find was that for a trip there was relatively little bulk compared to diapers and, barring a leak, your skin stayed completely dry. However the fact that I would so often have a leak never gave me the confidence I needed to use them in a public setting. I tried several things to hold the leg bag such as special leg straps, leg sleeves, briefs with pockets for holding the bag, and even a suspender belt arrangement. These worked better then the the cheap leg straps that come with the bags, but there were still issues, mainly with kinking. I honestly think I tried everything (even the Men's Liberty version) to make them work well enough to give me complete confidence in them but never got to that point. Compare that to using diapers in which I have nearly 100% confidence and my choice became obvious.
OK, all of that said I started thinking why anyone would want to use a condom catheter and came up with a rather interesting thought. Maybe it has a lot to do with the extreme stigma of wearing a (OMG!) diaper. I'm sure that for a huge majority of people the thought of wearing a diaper is horrifying, and might drive people to use any other alternative, especially so if a doctor were to recommend it. Not to mention that so many people have been led to believe that urine is "dirty" and something akin to nuclear waste, that they want absolutely nothing to do with it ever touching their skin.
OK, these are just some of my experiences and thoughts about this topic and I suspect that external catheters have worked well for some and would like to hear from those that have had good luck with them. Other comments are of course encouraged.