It's kind of like, "What's the best bike...?"
In reality, most of the leading brands are all good. It's hard to go wrong with one or the other. So when I am shopping, I usually look at price. Right now, the TKC 80s aren't as expensive as they used to be. The Shinko 805 is a bargain. Some of these new tires are EXPENSIVE! Unless they have some super compound that lets me get big miles out of them, I won't be buying them any time soon. That said, unlike some folks, I don't ride them down to the chords. I like having a bit more tread when I go off the pavement, especially where sand is involved.
As far as how well any of the adventure tires handle on pavement, I had no problem dragging my Jesse bags on my 1150 GS when running TKC 80s front and rear. I cannot recall them ever feeling unpredictable or doing anything unexpected. In places like Arkansas and North Carolina, I've been able to use pretty much the WHOLE tire from one side of the tread to the other. This is one of the reasons I quit running Jesse bags and prefer to run with just a top case if I can.
This is at about 75-80mph on TKC 80s. The foot pegs got a bit of grinding going through this corner. It never felt squirmy or mushy.
I cannot say the same for the Shinko 705(?), which is a more 50/50 tire. Even at moderate speeds, they tended to slide in corners on DRY pavement. I ended up removing them LONG before the tread wore out because they were just down right SCARY!
I tend to stick with tires like the Shinko 805 and TKC 80 just because I almost never go out for a ride that does not involve dirt roads. Many of the roads around here have sand, mud, deep gravel, big chunky gravel, etc,... My new GS has the TKC 70s on it. They are great on pavement. I am not real wild about them off the pavement. They just don't feel planted like the TKC 80 front. But, if I were going to do some kind of dual sport road trip, they would be high on my list. If prices ever come down, I might try some of the other more aggressive dirt biased tires.