I ended up buying the Martha Stewart Transfer Adhesive (liquid form). I tried both dabbing the adhesive on the sponge, and dabbing the stamp directly into a little adhesive on a piece of plastic. I have to say, I like the results much better than a glue pad. I didn't notice much of a different in the way I applied the adhesive to the stamp. I don't think it would give a real crisp image with a stamp with fine details, however, because it is a bit on the thick side. One big advantage with using the adhesive is it's white, so it was easy to tell what parts of my stamp were covered with adhesive.
I tried loose flocking powder, flocking sheets, and fine glitter. They all seemed to adhere really well. I also tried flower soft, which stuck much better with the transfer adhesive, compared to regular glue pads.
It does take some practice to get the right amount of adhesive on the stamp, but I didn't find it "pull my hair out" frustrating.
I tried both rubber and clear cling stamps....both seemed to work fine with the transfer adhesive.
Clean up was super easy as well-just used my unscented baby wipe as soon as I was done stamping. The transfer adhesive also seemed much easier to clean off of my stamps than any glue from a glue pad.