I'm in the same situation. Perhaps you should mention your system specs cuz you'll have different cooling needs depending on your components. My Problems are as follows.
FT02, it's nice and all but no thought has been put into those hard drive cages. There is no space between them. So if I shove in all 5 drives, there is no ventilation between them. This is the same will all other Silverstone products. It's perfect if you don't plan to fill up those hdd slots. On the plus side, the 90 degree motherboard orientation is really convenient. Basically, I can use all those back I/O ports on the fly, rather than having to wrap my hand around the case and feel where the port is to plug stuff in. This is the biggest plus for me. I know so because I own a Raven. However, the hdd thing really upsets me. In my raven, I'm only running three hdds, using the other hdd slots to space out the drives.
R3 is very nice. Temperatures are not FT02 but is good enough for my case. It is a looker. Problem with R3 is front fan filters are screwed on, which is a PITA to remove/clean. There's not enough clearance around the back side to hide my non modular PSU cables. Optical drives aren't tool-less. Other than that, I really like this case. It looks amazing.
550D looks good but I really don't like how the front IO is placed through a hole in the front door. I can't leave my phone or camera or other crap plugged in while accessing an optical drive or fan control, etc. It's also kinda ridiculous that the motherboard section is recessed. This leaves less room at the back for cable management. Door is not magnetic.. which kinda sucks.
That leaves the P280. Easy to clean filters. The PSU filter is removed from the side.. which is awesome for me rather than feeling around the back to pull out a filter. IO ports not affected by the door. Door bends 270 degrees. Only issue is it's probably the noisiest of the bunch and complaints about loose side panels is a concern. I hate the power light and hdd lights on this case.. stupid small blue dots on either side. I think if I block the top two ports completely, noise should be pretty good. I think cooling potential with this case is higher than the R3 and 550d because it is more open.. at least from the front. I don't think its in the same class as the FT02 though, with its huge 180cm fans.
If you got cash to burn, you can always look at the Cosmos 2 as well.