In this area, our coyotes tend to run on the "small" side. I get away with using #2 longsprings quite well on them. The jaw spread is nearly identical to a 1-1/2 coil, also. The #2 grabs coon way too high, but not nearly has badly as the larger more traditional coyote traps. This #2 works well for me for fox and cats too. We have such a high people population, as well as domestic pets, in those areas where I have permission to trap. I keep things as small as possible but still get me the job done.
Because of size of animals, size of their feet, etc. it is nearly impossible to say "one size fits all" approach and go with just one trap size and model. I also lean toward longsprings. I prefer #11s for coon, and have actually held a number of coyotes in them, too. But this is way too small for serious coyote work. Double jaws give enough stiffness to keep them from popping out. Got a cat last year in a #11 too. But again, that would be the exception more than the norm. I prefer the #2 long for the bulk of my dirtwork. Not that longs are better than coils either, I just own a bunch of the longs and have refined my techniques to make them work for me. They were also cheaper for my initial purchase. I've since dumped a lot of money into them to beef them up and make them perform better for me. I could have done the same thing by starting out with a good coil spring model and saved myself the effort and still had just as nice a trap to use. I didn't have the cash at the time, though.
Again, ideally I don't like the one size fits all approach, and each trap model seems to have its own pros and cons, but myself I have gone to a simplistic approach by carrying a lot more #2 longs afield these days. Again, I can get away with it well around here because I believe our coyotes are smaller than say their Northern or Eastern counterparts. A really big male on my line, one with worn teeth, etc. would be a biggie if it approached the #25 pound mark. That puts them really close to huge coon, a big badger, and mature big-footed cats, too. Most domestic dogs feet are much larger than than any of these animals, too. If I keep my traps on the small side, I don't seem to suffer much in fur losses but sure go easier on the accidental dog and cat catches. I've caught a number of coyotes by both front feet in these #2 longs, too. I make them work for me, but it was some trial and error too.
Jim-NE