I ride a 98 Harley FXDWG, it has the stock foot pegs and I have highway, or forward mounted foot pegs as well. I am not sure that I would be comfortable with just forward controls as I need to change up my riding position on long trips. I also like to have my feet on the stock pegs when I am getting into any tight curves or where a concieved requirement of techincal riding may be present. I feel that I have better control of the bike with my feet below me, versus in front of me.
I like to ride long distances and find my body just needs to change up positions and/or to strecth out my legs, (34" inseam....). I also like to stand-up occassionally to further stretch for short periods at lower speeds. I have not tried foot boards, don't know how they would be??
Sometimes on long trips on the highway, particularly freeways where one is unlikely to require immediate response, I will hook my heels over the passenger pegs behind me, again this helps to strech out the legs in a different position, ...a change is as good as a rest sometimes.
My last bike was a DL 1000 V-Strom with stock foot pegs, ..kinda wished I would have had "highway pegs" on this bike to stretch out.
Bottomline, ..I don't know that I would want to be restricted to just forward controls.