Why types of food do you generally smoke? Do you do a lot of ribs where you wouldn't want to cut them in half to smoke them, full packers, etc? Some of the smaller smokers (like the MES30 and the Masterbuilt 2-door propane) aren't very wide. Do you do much for smoking things like summer sausage/ring bologna/dried beef?
I have both an MES40 (which may be a bit out of your price range) and a 2-door Masterbuilt propane. I used the propane for years and really liked it (supplemented it with the A-Maze-N tube smoker) and like it. But when I started making sausage had trouble keeping the temp low enough without losing the flame, so went to the electric, which I use mostly now (until I get my new Bellfab offset here shortly I hope).
My experience the MES are good and with the tube or pellet A-Maze-N smokers are basically "set it and forget it" for lack of a better term. The propane you don't have to baby much, but at least to me the external temp/wind changes would mess with it some. So if I got it set early in the morning, by mid-day temp could be different.
What type of smoker do you have now? Guys have had pretty good luck it seems like with extended cooks using things like the Digi-Q.