I have had a 2-bike version of the Saris Cycle-On Pro for going on two years. It is an expensive bike rack as car racks go, but I was determined to avoid a roof rack and I wanted the bike and car as far apart from each other as possible. The design of the Cycle-On Pro does all that, and that has been a good thing. I have mine on a 2-inch hitch receiver which is stronger, and is required if you want to mount an extension platform for an additional two bikes (I don't, but I thought it would be stronger and got a 2-in. aftermarket hitch receiver put on by U-Haul. My car, an Infiniti FX35, does not have a receiver standard.)
I can make several observations. First, it is best to have a receiver at your bumper height, since the extended bracket and tensioning knob can scrape easily on driveways and other steep road surface changes if mounted to a receiver lower than the bumper. It limits the approach angle and damages the knob by scraping on even modestly steep approaches, like driving off driveways onto highly-cambered roads. Second, the hardware I received with mine, which you need to bolt it together (as the carrier comes partially assembled) has a tendency to rust badly over a short time. I leave my carrier on the car most of the year as I travel with a bike whenever the weather allows, even in the winter here in Maryland. I suggest that until Saris decides to spec stainless bolts for the rack that you swap out the cheap fasteners they have and use stainless instead. Third, the racheting arms that brace the front bike wheels are susceptible to corrosion and the spring mechanism inside will freeze as a result. I have had Saris replace both not two years into my ownership from new purchase. In fairness to them, they honored the warranty without a fuss and sent me replacements, but keep in mind that you might need to do the same if you live anywhere where there is wet weather, or near the coast or where they salt the roads in winter. Last, the rear wheel cradles which are made of stamped and formed powdercoated sheet steel bolted to the rack frame have corroded particularly badly, enough that I think they were not properly coated at manufacturing. I had to remove them, sand, feather and prime and repaint them this spring because they were so rusty (good old Rust-oleum.) I suppose I could keep the rack in storage, but my expectations of this piece of equipment is that it should be able to stand up to weather and typical road conditions. My car isn't rusting to pieces and neither should the rack.
On balance, I don't regret buying the rack. I like the convenience of a low carrier (used a Thule roof rack for years on lower-height vehicles) and the only similar model was the Thule which none of the shops in my area carried. I don't think I chose badly between the two.
My recommendation to Saris is that they work on the corrosion resistance of their design and that they improve their powdercoating prep.