I've never had the opportunity to use a Tuff 1 ratchet. I have standard "professional" SK ratchets in 1/4, 3/8 & 1/2 drive, and a 3/8 bent flex head, and I have no complaints at all.
The body of the Tuff 1 looks very much like the Professional body, twice the number of teeth, and it's still made in the US with a lifetime warranty. Hard to go wrong.
As Deafautotech pointed out, unless you have a SK dealer nearby, you have to mail it to SK for warranty... I don't wrench for a living so this is not a big issue for me, but it is something to consider.