You can fit 140mm fans in front but they have to be mounted internally. If someone really wants a push pull setup, it can be done. I've seen pics and read comments from a guy that remove a few small plastic pieces and mounted his 140mm outside behind the grill like the stock 120s ( this would permit permit a push pull setup with 140mm). On my end, I have 2X140mm mounted internally (low noise high CFM etc..)
I installed a closed loop for the CPU 120mm push pull on the back, 2x80mm at the bottom as exhausts and a low en 200mm (not 20mm thick) a normal 25mm thick would hit the radiator thus preventing the top to close.
Its a really good case even compared to my Cosmos S all fans installed and a few years later moded with 2 powerful 120mm and a really good 92mm in the door to replace the large fan. Every single component runs cooler, with fewer fans so way less noise.
There are a few minor downsides. Though its a dream to work in when tweaking a completed build, parts in the bottom compartment are hard to access. The other downside IMHO, my old may drive was a velociraptor which means it cant fit in the doc. Good thing
I was switching to SSD or else I would have had to lay it down inside either side panel (plenty of room). The top fan mount only supports Cooler master fans (my only real gripe with the case). Since everything from my monitor to my keyboard have USB ports I didn't mind that the front USB was unusable with the older x58 borad.
Bottom line, I used to prefer huge cases, starting with the original STACKER but this one hit the spot. yes I can't get to the stuff in the bottom but I replaced my x58 with a Z77 so fast and so easily that it would be hard to go back to any other form factor and accessibility features.
PS. long post..yes and from someone that never posts anywhere and just because I love this case so much!