Traction- YES I get trials tire traction from a knobby without the things I disliked about a trials tire.
Feel- YES It is lighter and it can be felt, I've ran TuBliss and then bought my current bike that had HD tubes when I bought it...I'm tight (broke) so I ran the tires out and I could tell a considerable difference when I mounted TuBliss on tire change over + with the lower pressure there is a grip difference in the front as well
One issue I had when originally changing over was that you need to run 'tougher' tires- on the same course with tubes & MX51s they worked fine with tubes but with the TuBliss & MX51s the grip was so improved that I pulled knobs out of the carcass- you could stick your thumb in the hole and I ran 2 hours on that flat. Problem stopped when I moved to stiffer tires + you don't have to buy top dollar tires, I get great traction/wear from Sedona tires at much less cost