I've got Keo Classics. I like them because the cleat is easy to align precisely on any shoe. They're easy enough to get in and out of, and I've never had a cleat let go when I didn't want it to.
I think maybe there's a bit more of a learning curve with these pedals than there is with some. It took me probably 3,000 miles before I could reliably get into the pedal without looking at it.
Cleat wear depends entirely on your individual conditions. How often do you put your foot down, what are the road surfaces like, do you always put the same foot down or alternate, do you carry cleat covers, and if not what's the farthest you'll walk before you'll take your cycling shoes off and go barefoot? I normally get about 2500 miles out of my right cleat. This time I replaced only the right one and I'm guessing I'll get an extra 1000 out of the left.
My Specialized Torch shoes have been fine. At 5600 miles, I'm getting ready to replace the ratchets and straps. They're vented just as much as the tri shoes, but in a road shoe configuration.
I will say one thing about shoes: I'm not a triathlete, okay, but I wouldn't want tri shoes as my only shoes. You'd have to live with less support and a flimsier upper on all your road and training rides, in exchange for a few seconds in transition. Try them on at the shop, fast as you can, and you'll see that it's probably a difference of 15 seconds or less to fasten and unfasten a tri shoe vs. a ratcheting closure. Now, if tris are really important to you, that 15 seconds could be all the time in the world. But for most people, I don't think it would be worth it to not have the support the rest of the time.
Speed comes from what you put behind you. - Judi Ketteler