But what if I run the cabinets in series?
According to the manual that should make it an 8 ohm load and since I have the C model then the output would be just as much as with running one on either side. But I have heard that with running in bridged you get a fuller sound than in dual mono.
How do you propose to run them in series? You're going to need a special cable. Daisy chaining them is running them in parallel. With an 8-ohm load in bridge mode you'd get 880 watts, the same as if you ran the cabs in stereo. I've never heard that bit about it sounding "fuller" in bridge mode, and I seriously doubt there's anything to it. I ran my WT-800B both ways and couldn't discern a difference.