Yes, the 11.75" rotors are very nice. The first thing I noticed is that it balanced out my braking front to rear, no more locking the rears first. Much more positive feeling stops.
And the bearing spacer thing just seems like a bad idea to me. I'm sure they work, but what happens if they spin? Can't be good for the spindle. I can see why that
shouldn't happen (bearing resistance should be low enough that it won't put enough force on the spacer to spin it), but I don't see why it
can't happen (especially if the bearing gets gunked up, or set with too much pre-load). It would obviously depend on how tight a clearance the spacer has to the spindle. Something to think about.
With the availability of later spindles, I just wouldn't bother with a conversion unless I were going to run BIG brakes, wilwoods etc.