For at a dump site with a direct downward drop, you can't get faster than a stinky slinky and with just one hose for the needed length, issues are far between. I keep one in my clipper just in case.
However, I don't stay at FHU sites and few of the campgrounds I visit have dump stations. So, I usually dump at home. In this case, the macerator beats the slinky. No leaking at hose connections; no dealing with imperfect lengths, turns, or rises in elevation.
Between the SS and the macerator, it's this:
SS - needs a good amount of water and water pressure
Macerator - needs a good pull of power
For me, at home, the power is more convenient than the water/pressure.
I have the portable flojet - it's currently $207 on Amazon. The Valterra SS is $75. Not a huge difference in price. When not in use, the hose is on the reel (dedicated hose for this purpose) and the macerator is in its box (as shown in Reddog's photo). No issues with space concerns.
Neither is a bad choice and for those who don't like stinky slinkies or have a setup that makes them worthless or near so, then pick the macerator or the SS that fits your needs/preference best. It's not a competition with only one right answer.