"Misses" happen, but IME, they are few and far between, and you can always try Uber as a backup. I've also been in some less-than-perfect UberX cars.
I also don't like not being able to pre-reserve a pickup from my home via Uber. I have to hope cars will be available and it won't be surge pricing. Not always the case for a rush-hour-ish pickup.
Net, I still prefer the traditional services for airport travel (and I usually buy-up for $5 to the "deluxe" car); I don't think the Uber premium is worth it on a regular basis. JMHO.