You'll lose power with anything if you dont get it set up right with a decent cold feed and appropriate mapping.
I came off the back of a Viper to a Maxogen and there's bugger all difference in performance, well, any that i noticed and the car was set up with each kit!
Maxogen quality is second to non but in terms of the performance difference there aint no ''WOW''
factor
It all comes down to personal preference at the end of the day
Makes me laugh when folk think they can tell a difference between 5 bhp loss or a 5 bhp gain. Not a chance in hell you can