IMHO you want to go with something that you will keep around 75% full; makes keeping the RH consistent much easier.
Most say go bigger than what you "think" you need, but if you've been smoking for awhile and are comfortable with the on hand qty you maintain....keeping it "mostly" full is more important, again, imho.
I have no real opinion on those two models; you do get what you pay for in most cases though.