I normally use the three-piece crimp-ons, but I've also used twist-ons in a pinch, and seen them in a lot of installations. I've had a lot more problems with the two-piece crimps, mostly because the shield crimps always seem to be significantly larger than the cable I use, and I just can't get a tight fit on them.
In my experience, the only time I've ever seen problems with twist-ons is when they're installed poorly - insulation not stripped back enough, or stripped back too much so the threads don't bite into it, etc. Of course, any connector type will give you problems if you do a half-assed job of it.
My only real problem with twist-ons is the pain in the wrists after doing any more than a half-dozen or so of them.
BTW, for those connections exposed to the elements, I find it handy to carry a tube of dielectric grease, the kind sold in automotive stores for coating battery posts and wiring harness connections under the hood. Goop some of that in there, then if possible, wrap it up tight in PVC tape (the stretchier, the better, to you can get a good tight form-fit).
Not much you can do about the "tire iron" calls short of installing Extreme CCTV domes...