So, at the moment i sit in front of an ThinkPad Twist and an IdeaPad Yoga 11s and i'll give you a short comparison.
Side by side both devices have an very different feeling.
The Twist looks like it has much more unused space and in therms of the build quality the Yoga tends more to an ThinkPad than the Twist in my eyes. On the Twist there is an glossy bezel around the glossy screen and also the spaces between the keys on the keyboard are glossy. The only glossy thing on the Yoga is the Display itself. The Twist is definitely more Edge then ThinkPad.
The keyboard on the Twist feels a bit better than on the Yoga(more like a ThinkPad ;) ) but compared to other keyboards they are both very good. Both keyboards should be spill resistant but on the Twist the blue LED attached to my ADATA SX300 seems out between the F-keys. And that's not a small gap!
Trackpoint is only available on the Twist. I loved the trackpoint and exclusively used it on all my ThinkPads (x220, T430 and now the Twist, trackpad was diabled continuous) but the trackpad on the Yoga is very good in my opinion and much better than on the Twist. The trackpad on the twist is slightly rough and slows down my motions. I think the smooth surface of the yoga trackpad is the better solution.
Touching the screen in laptop or stand mode is nicer on the yoga too. Compared to the rotating hinge on the Twist, the Yoga hinges observing the wobbles of the screen a little bit better.
The displays itself are very good on both devices but its a bit brighter and richer in contrast on the Yoga.
The Twist has an mSATA and also an 7mm 2,5" HDD/SSD slot which i miss on the Yoga!
I'll stay with the Yoga 11s. For me it's the perfect combination of performance and mobility(only missing integrated WWAN).
Just my two cents ;)