Is there any practical difference between the two?  I'm looking for opinions on your preferred method of mounting and indexing muzzle devices.

We prefer Crush washers, just less time & energy spent indexing the break - jmo

Peel washers allow for a better balance of torque and alignment. True, it takes more work and time,  But, what does it mean to us in NJ, nothing.  We end up frigging with the end of the barrel for stupid reasons anyway.

Peel washers allow for a better balance of torque and alignment. True, it takes more work and time,  But, what does it mean to us in NJ, nothing.  We end up frigging with the end of the barrel for stupid reasons anyway.

That is more or less true.  However, for my next upper build it's more of a federal fly in the ointment.  I'm building an M4 type with a 14.5" bbl and have to "frig" with the linear comp anyway to appease Uncle Sam.  Since I'm going to have to weld that sucker on, I wanna make sure I'm using the best method for spacing and indexing.

Well in that case the 16" minimum rule comes first, of course. 

Neither is needed for NJ. Belt sand the back of the brake to get your alignment, then weld away.