488RC4 vs 488RC0 Ball Heads

I recently purchased a Manfrotto 550XPROB Tripod and I've been considering the 488RC4 or 488RC0 head for it. The RC4 plate is rectangular while the RC0 uses a 6 sided plate. Specs for both seem identicle so I'm wondering if anyone has used both and which one is better, or are they essentially the same. The cost of these are almost the same ($115) and that's about all I want to spend so I'm not even considering RSS or similar heads. My heaviest lens is a 70-200 f4 IS and a 24-105 f4 IS. I sometimes use a 1.4 extender as well. Any suggestions would be appreciated.

Thanks

Go with the RC2 instead of either of those. It's not as big and bulky, so you won't be tempted to remove it from the camera when you're not using it on a tripod. Those two are mainly for larger-format cameras, from 2-1/4 on up.

I have had all three sizes, still use rc0 for video cameras, but it is big and gets in the way on my still cams. RC2 is my standard for all still cams now.

The RC2 will probably work the best for dSLR's. I have the RC2.

I have used the RC4 and RC2 plates and while the RC4 plates are more stable and secure, they are huge and bulky. The RC0 plates would suffer the same over sized design and bulkiness. The RC4 and RC0 are just not made for 35mm sized cameras. They were more designed for medium format cameras and are sized accordingly. I would highly recommend you bypass bogen all together and go arca-swiss like Really Right Stuff, but I do realize that cost is a big factor there.

Another recommendation for the RC2 system for EOS cameras and associated medium large lenses (which have tripod mounting rings on them).

I just accidentally got sent the RC4 instead of the RC2 and can tell you its way too bulky for my XTI.

One nice thing about RC2 is that it's small enough to not get in the way when handholding. I always left mine on.