Exhaust is always better. Remember the el-cheapo whiteboxes (and even some name brands with micro ATX cases), or even older systems? One cooling fan, and it exhausted air.
And brute force (aka the “Get a Bigger Hammer” approach) does work, but only use it when brute force is absolutely necessary, such as in a fully loaded system and SMP systems, but even then you still need a basic plan (e.g. in the front, out the back).
Removeable trays, even good ones, tend to shudder (ever so slightly) and shorten the life of the CPU fans and weaken connections on watercooling systems, where a non-removable tray shudders with the system as a whole unit (which is acceptable). The shuddering also shortens the life of several other core components in the system, although not niticably (fans, hard drives, … anything mechanical).
While they’re convienient if you swap alot, they aren’t the optimal solution if you’re only installing your mobo once per case and never reinstalling it. Personally, when I buy a mobo, I buy a case and never take it out. Power supplies get swapped, but generally I install in a big enough case to allow for maximum future expansion. On the other hand, my motherboards tend to cost more than a good quality case.