I do on all my coils.. It's kinda overkill
for the sniper as it's totally plastic enclosed,
but the stock and 9x12 coils I wouldn't use
without covers.. But thats just me...
It's no requirement, and they work fine as is
in most cases, but I prefer the covers as the
epoxy bottoms of the coils don't get chipped by
rocks, etc..
All my coils stay like new. I do have to remove
the covers every once in a while to clean, but
thats no biggie. Any metallic dust under the coils
can cause falsing, but it's never really been a
problem so far.. Probably cuz I clean my every
once in a while. I bought the sniper coil cover
when I bought the coil, so I wasn't sure if it
needed one or not.. It really doesn't, but I
guess I got double protection..

One reason I like the covers is I often scrub
down pretty low. With the cover, I don't have to
worry about dinging anything. And that lack of
worry may gain me an inch as I scrub down lower than
I would with no covers.
MK