Apologies up front, this isn't going to be a definitive reply just some ramblings...
I used to have a vertical propane smoker and a propane grill. A couple years ago I went to a PG500. Haven't used the smoker nor the grill since. No regrets, I don't see a scenario where I would ever go back.
I hear ya about grilling on the PG not being ideal. Hard to see and a bit cramped. But I LOVE the flavor of things grilled on the PG. Way better than on the gas grill. I also believe the PG gets hotter and gets there way quicker than my gas grill.
I truly believe my PG provides just as good smoke flavor as the old vertical smoker. I have also been surprised that meat smoked on the PG is just as moist as what I got out of the vertical smoker which had a water pan.
My situation now I only have to maintain and keep 1 rig clean. Only 1 rig occupying patio space. Etc.
I also always hated filling propane bottles. Man do I love not having to deal with that anymore. May be trivial to others but was a PITA for me.