trials tires: volume or casing?

The Pirelli MT43 is extremely popular. Is the advantage from the huge volume, or is there something gained by a different casing material? I looked at a 4.0 MT43 next to a 4.0 shinko 244, that thing is huge!! Isn't the extra large size a noticible detriment to handling since the bike was designed for something smaller? Is there anything else that is almost as good, but a little smaller? Has anybody tried the shinko 241?

See my post here for info:

http://advrider.com/forums/showthread.php?p=20888674#post20888674

Trials tires grip by wraping around stuff, the side walls are tall and soft so it can do that.
IMO a tall rear tire makes the WRR handle worse.
The mt43 is popular because it last a long time and bites ok, if you can aviod mud its a good choice.
I've ran one it didnt work any better anywheres than a good knobbie and sucked in mud which I end up riding in often, but it lasted longer.
Trials tires were a bit of a fad, the only place they work better than a knobbie is pure rock riding and the mt43 is the worst biting trials tire but is the only one that will hold up on a enduro bike. I know guys who run trials tires for certian races, they run the dunlop803 as it bites way better than the pirelli.
The key to making tires bite is running the lowest presure you can get away with, drop a knobbie down to 5-8psi and it will have tons of grip.
To do this and not get flats you need the newtech tubliss system, IMO its awesome for dualsporting as any tire bites when run close to flat lol.
The shinko244 with the tubliss system so you can safely air way down would work almost as good as a trials tire and last a long time just remember to air it back up when you hit the road.