Have you tried removing and then repacking the old grease? I would look into this, especially if yours is an older Hobart-era one, as those should last forever. My newer model started sort of surging and slowing down a few years ago, I cleaned out and repacked the grease around the transmission and that took care of it. I remember I had a little trouble finding the grease, but the job itself is not too difficult outside of being very messy.
Edit: I should also add that I have owned a 7qt KitchenAid Pro Line for a few years. It is great for large batches of things or bread doughs, but I find that smaller volume recipes usually need a few stirs by hand to get everything incorporated as the bowl is huge. They make a paddle with a silicone scraper attached and it works pretty well, but I still find myself getting the smaller 4.5qt model out (the one I replaced the grease on) for just a normal batch of cookies or whatever.
