the FD R4 is a amazing case. if using the HDD cages, the OE fans are pretty meh. would need a better static pressure to push air past the HDD cages (as all cases should do this). and if in the future water-cooling is a thought, this case can accommodate a pretty good loop for CPU/GPU. the 650d is a fair case (dated) but the price point is far above the R4.
NZXT Switch 810/820 can hold a 360x 30/45 easily and if using SLI/CFX can hold a 240x 60 in the floor or front intake.
the bottom 5.25" bay has a perforated plate (wiggle the plate forward/backward) to remove. if reinstalling the 5.25" to 3.5" adapter and need that re-installed, the two screws in the parts pack hold the plate to the chassis.
im glad someone else had noticed. i'd thought it was "trending" and recovering from holiday sales. but its passed into the used RAM market. excellent graph and acknowledged..