I use a Menda pump most of the time. (Pure touch stainless steel lid/glass container, frost blue color) for extremely busy times, solid no glitter acrylic.
The pure touch lid is made so the liquid doesnt re-enter after it has been pumped out for use.
Dapen dishes when applying glitter/mylar with acrylic.
I like using the Menda pump more, just because I dont have to take time filling my dapen dish.
I like using the OPI heat eq, and I can't do that with a Menda pump.
As, a previous post stated, you have more control over smell,vapor, and all that.
Oh yes, I can't stand the fact that the Menda pumps made for liquid monomer don't have permanent lettering, and the labels that are supplied fall off.
Some of their plastic bottles are premanently labeled.