Won't fug up your harvest. May get a smaller yield. The fall sun is more gold in color so HPS mimics that sun. Don't let anyone tell you different. It's that simple. I've done both, HPS is best in flower.
Hey Hank,you say you have done both, but did you try switching to HPS after stretch? i think that makes the most sence - as MH does keep stretch down & makes more more internodes...so veg with MH then keep them on till like week 3 of flowering, then switch to HPS