I appreciate the message, but that checkbox actually relates to
using the graphics card to accelerate certain operations, which
TenFourFox actually doesn't support. As a result, the checkbox
actually doesn't do anything in the current version. It is present
in case we get some variety of hardware acceleration operational in
the future. I don't have an explanation for the difference you
state you notice.
If I actually misunderstand what you're referring to, a Bugzilla
number would be very helpful.