Just don't go overboard with gee whiz stuff and lose the useful load.
Even if you plug in two full PFD/MFDs from Aspen, a three-axis autopilot, radios two full sets of back-up "steam" instruments, an EFIS, and all the other "gee whiz" stuff that would make any airline pilot jealous is under 90 lbs. Then again to me 90lbs isn't that much but for the really light stuff (RVs and below) it would be.