bitflipper
It's a complicated tool and not very intuitive. There's certainly room for improvement in terms of usability. But for everyday timing tweaks it does in fact work as advertised. At least, my version does.

I agree, except I'd add that in the article I wrote that's linked to above, the use of the word "tedious" was chosen carefully. AudioSnap is a perfect example of Anderton's First Law of Audio Correction:
 
"Correction works best on audio that doesn't need a lot of correction"
 
This applies to pitch correction, beat correction, noise reduction - you name it. That said, I'd be the last person to say that AudioSnap is a joyful experience, but I'd also be the last to say it's useless. Like Bitflipper, I mostly use it manually to correct things that sound "off" - although the Sound on Sound techniques article does illustrate an example where I needed to snap a mechanical kick to a human kick (it worked fine).
 
AudioSnap 2.0 is now almost five years old; when I reviewed it in SOS after it was introduced, I called it "the process Sonar users love to hate" and noted that a major problem was that people didn't realize that when you listen to an AudioSnap clip while editing, you're listening to a lo‑fi preview mode. You need to render the file, using one of the iZotope algorithms, to get full fidelity so you have no idea what it will sound like until you've rendered it.
 
The bottom line for me is that AudioSnap has limitations. If I work within those limitations, all is well. If I don't, it gets frustrating.