I am kinda in the same boat. My bike came with a yamalink installed which at 5'10" means I can just flat foot it with dirt wheels. I like being able to flat foot it, but not at the expense of handling. I have heard many people say that it messes up the geometry but I don't know what that means. If you lower the rear 1" with a yamalink and are only able to lower the forks a 1/2", then that will change the geometry But going from 17" street tires to 18/21 dirt combo is a much larger change in that regard.
The yamalink does soften the rear suspension I believe 10% it states it on their website. This can be good or bad depending on your weight. One of these days I will try without the yamalink, just to find out for myself what happens. Post up your findings if you give it a shot.
Make sure you set sag on your bike, and if you change links you will have to re-set the sag. If you are riding on road only I don't know what sag you should run. Probably check on a supermoto forum. I would guess you want less sag because less sag means less weight transfer forward/back when you are on the gas or brakes but who knows.