LOVE my macerator system for a lot of reasons. First and foremost I don't have to EVER touch or wrestle with a "stinky slinky" again. Having spent years doing it both ways I see no major difference with tank cleanliness. My current 5th wheel didn't drain great before or with the macerator so I often just leave my outdoor kitchen sink faucet running when dumping (it drains to my black tank) and cycle my macerator on/off a few times at 3-4 minute intervals to float all the stuff off the bottom of the tank.
There are a lot of other benefits to the macerator system as well. When camping I usually just hookup the 3/4" hose and leave my gray water open and that's all I need to deal with until I get home. No more waiting in line at the dump station, no more insisting the kids "hold it" all the way home. Of course, these things have more to do with just coming up with a way to empty at home but for me the macerator is just a really nice overall option. I'd still use it if I had a 3" cleanout in my driveway. It's just so much cleaner and easier.