Just weighing in with my 2 cents worth, (late to the party again). I have had mixed results using FP+. Sometimes, I get exactly what I want, and sometimes, not...but the I usually go to WDW when the crowds are low, never during crazy packed times. And, I guess my main goal is not to get on all the rides numerous times...I really enjoy just being in the parks and people watching, and of course, shopping. I've often missed my FP+ time because I was doing something else, or couldn't get back in time, and (just talking about myself here), often it didn't really make a big difference to my overall happiness that day. If I can hit my favorite rides a couple of times during my visit, I'm a happy camper.
This past trip, we also did a day at Universal...and while I was there, it struck me how different these experience are. Universal is really a RIDE park, more of an old fashioned "amusement" park kind of place...Disney is a "immersion experience" kind of place - with rides. Universal SELLS express passes so you can go to the front of the line...if you want to hit lots of rides, you buy the pass. Disney gives the FP+ away as fairly as they can so everyone has a chance to get them...not really working as they envisioned, I'm sure, but there it is.
So, my question is, would you rather PAY for a front of the line pass like at Universal? I know sometimes, I probably would, and sometimes I wouldn't... But I can hear critics saying that offering a "Paid Express Pass" to the mix would just makes it more elitist...