Grab a beer, pull up a chair, and let your helpful uncle Mike tell you a story.
Once there was a guy who didn't take his own advice and left a differential drop kit on his 2006 Tacoma 4x4. He put lots of time, effort, and cash into modifying his skidplates to work with the kit that he never should have installed, He did it to protect his precious CV boots.
Then he went offroad, after which he could no longer drive his truck. The end.
When told that the diff drop does nothing but pivot the front differential, there are always a pile of people that say "Even if it only helps CV angles just a little, I'm going to use it." They can kiss my ass. (that's probably the beer talking but the sentiment is not that far off )
This is not a debate. Remove those spacers.
My truck looked like this:
Then I hit a rock because the differential mount was sticking too low. My truck then looked like this:
Let's pull that skidplate and see what we've got...
^ Note that the passenger side is no longer lower than it would have been had I left it alone. It's right where it should have been all along.
It got that high by pushing through the cross member.
It didn't just push up either. It pushed backwards, and the differential became intimate with my oil pan.
http://i255.photobucket.com/albums/hh149/mjp_2/IMG_3053.jpg
The bottom end on my engine is playing peek-a-boo:
And to those that swear these things actually help, look at where the dropped mount is relative to where the front axle inserts into the front differential:
Pretty nice looking mount too, huh?
So...how much of a pain is it REALLY to replace a CV boot?