I'm going to give you my recommendation first, in case you don't want to read my whole rant.
Saw is a well made horror film. From what you've stated about your taste, I think you might enjoy the first one, but probably not the sequels. It is more disturbing than scary, but then again, in my opinion so are all the asian horror films that you said you enjoy. Also, the theatrical cut is the only one available on Blu Ray, no director's cut.
I haven't seen The Descent yet (I'm waiting for the price to drop on the blu ray) but I've heard really great things about it.
I always find the whole "torture porn" thing so hilarious. Watch Saw (the first one anyway) and point out to me where all the gore is. Seriously, in the theatrical cut every bit of violence happens off-screen, there is absolutely no gore whatsoever. There is a bit in the director's cut but nothing extreme by almost any standard. The sequels have gotten progressively more out there but, at the very least, the first one is a quality horror movie. Not "boo scary" but disturbing.
I would be really interested to hear everyones' opinions of films like Dawn/Day of the Dead, the Hellraiser movies, and Argento's films. Horror films from before the whole 90's, kiddy, PC, pg13 era were right up on par with not just something like Saw(in which, as I said, all the gore is off screen), but also with something like Hostel which really IS all about the disturbing gore.
And you know what... I'll bet you that even someone like Tom Savini who was involved in the genre can look past any cloud of nostalgia and enjoy what is being done rather than sound like someone pissed in his cornflakes.
Do you have a link to support your existence?