Taking another bios and using it on a different board can certainly have positive results..
I flashed my Maximus X38 board to a Rampage X48 bios and the results were pretty decent.
As for for modded bios a word of warning make sure your modded bios is from a trusted source and its tested
There are a few so called mr.bios out there and they brick more boards than anything else, some wont even test there own work wich should tell you something about there skill level.
I've used some before and found no benifit, no higher FSB clocks, ram would not clock higher, bandwidth remained the same.