I owned the original Antec 900 for a couple of years, and I like this case A LOT better. I'll look into the details to make sure I haven't forgotten anything, and I'll post my opinions on the 900 as well. I could check out the 902 as well, I'm not sure how much better it is than the original.
EDIT:
The comparison to the original 900 is pretty much exactly like the comparison to the HAF932 above, except the 900 doesn't have enough cable management holes or a cut out for CPU cooler installation in the motherboard tray. The 900 does have a "L-M-H" fan speed control switch on all of its case fans. The 900 can be had for a lot lower too though, $100 shipped ($80 shipped AMIR). When I bout the 900 I got it on sale for $55 shipped.
The Antec 902 looks like the direct competition to me at $130 shipped. The only difference between the 902 and the 900, that I see, is that the 902 has the black interior and a huge cutout in the motherboard tray for CPU cooler installation. It still seems to be missing a hole close enough the the PSU so you can optimize your cable lengths. The 902 uses silver/chrome screws and screw requiring a screwdriver on the PCIe slot covers, but those are minor details.
So, the comparison between the 902 and the R3 is a lot like the R3 vs HAF932 comparison as well, except remove black interior from the R3 list and replace with better cable management. Example: On both the 900 and 902, the hard drive SATA/Power connectors stick out towards the motherboard which could cause issues with some GPUs. Plus, with the hard drive connectors towards the right side panel like in the R3, it makes for a much cleaner look.