Have anyone tested the maximus with all pci-e slots filled?

I´m thinking of going for 3 x 3850 or 3 x 3870 just becuse I can =). I´ve read several reviews were its stated that the third card wont do much of a difference, but maybe the maximus can make better use of them?

They are selling 3870:s with 850 mhz core for as low as 130 usd here in sweden at the moment. Ever since I got my maximus extreme I´ve seen a inner picture of three 3800:s crossfired there in the case, and with these prices I almost can afford it. I´m sure alot of you gonna say, Get a 4850 insted or get a 4870 , but anyway have any one tried 3x3800 with this mobo?