i started out with a 30L fermentater then got another one and 2 pads. now I have a 120L and 2 60L fv's and only use the pads occasionally for bottle conditioning in winter. Having the pad under the yeast never looked right to me either, but I can't say I think it ever caused any problems like off flavors that I could tell. I only do apa's/ aipa's though which might mask anything minor. Ideally, IMHO you want a belt, an stc controller and a camping mat for each fv. With a bit of rooting around you could regulate the temp with a timer. that should do ya for winter anyway....