Wait, which maps have you needed to use a decompiler for? All the maps you've flipped so far have been included in the SDK... haven't they?
Valve make minor tweaks to maps from time to time.. Without knowing specifics I'd rather decompile the current version in the game and be sure to capture any exploit fixes than use the potentially out of date sdk vmfs..
That said I dont think Vmex is as acurate as I had first thought.. so with 2Fort specifically I had to spend some time checking settings on some props that had dodgy shadow and lighting settings. I also had to copy over the visclusters and occulders from the sdk vmf..
Last night I decompiled Degroot using BSPSource and found that it did a better job of retaining individual model settings. Ill be using it for any future maps that I decompile.