I have the EcoHitch and it is a hidden hitch, and all you have is the insert square just 2" where the oem hitch would be. Changing the shape of the bumper for a hitch was a negative in the aesthetics for me.
But yes, you could slightly more clearance, BUT, keep in mind, if your HL rear is being pushed down to the point that its effecting clearance, you potentially have more issues with reaching and PASSING tongue weight max. This with heavy loads can be a problem to say the least.
If you use it as a bike rack, the lower sitting og the receiver helps in that the fold-away style bike racks gives you enough clearance to open the rear hatch. Some have reported with the OEM hitch, they are not able to lower it enough to open the rear. Just something to consider, and get the one that works for you. SO far, Heavy towing, its the Curt hitch. Bike Rack and not cutting or messing up the straight shape of the bumper, its EcoHitch. For staying with Toyota or some potential height clearance issues, OEM. Cargo Rack I would think either one works fine. But heavy loads the OEM may help with drive way rub.