Bikeradar basically said they couldn't get through the Fahgettaboudit or the On Guard Bulldog Mini without a power tool. With a power tool there was about a two-and-a-half minute difference in cut time. The Bulldog got 4 stars and the Fahgettaboudit got 4.5. So according to them, no major advantage to the Fahgettaboudit other than cut time.
Raleigh Grand Prix, Giant Innova, Nishiki Sebring, Trek 7.5FX
The best three in the security game are Kryptonite, OnGuard, and Abus!
All three make anywhere from down right crappy to excellent locking mechanisms or devices. The New York Fahgettaboudtit U Lock I personally believe is the best in U Locks. That would be closely followed by the Onguard U Lock.
I know the Fahgettaboudit is thicker and will therefore take longer to cut with a power tool. But a couple more minutes probably won't make a difference if a thief is using a dremel.
Is there any kind of attack that a Fahgettaboudit will stop that a Mini Evolution or Bulldog Mini wouldn't also stop?
The 18mm cross section of the Fahgettaboudit's shackle contains about twice as much steel as the Evolution Mini or the Bulldog Mini, at 13mm. The Fahgettaboudit also has a double-deadbolt mechanism that secures both ends of the shackle (as does the Bulldog Mini), so cutting the shackle in just one location doesn't effectively open the lock, unlike the Evolution Mini where one end of the shackle's secured by a bent foot. And the Fahgettaboudit has a double-walled crossbar to protect the locking mechanism.
For the record, I doubt any thief is going to attack a Faghettaboudit with a Dremel proper. A full-blown cut-off tool, perhaps. If I were a bike thief, and were determined to cut your Faghettaboudit, I'd be considering an oxy-acetylene torch. But first I'd see if I could just cut what you've locked up to, it's bound to be the weak link unless it's a gas main or a big electrical conduit.