Mine is a Bracketron mobile dock-it. It works OK, but not what I'd consider great. I don't like the lever thing that creates the outward pressure in the cupholder, and if you don't use the sticky pad at the bottom, it flops around. The newer version of the Bracketron mobile cup-it looks like a better engineered unit in that respect. I like the head of this mount a lot, giving access to the charging port, and good grip.
What it also does well is rotate, angle and stay in the spot I put it.
The Arkon you mention looks like it should work if you can accept the rigid riser. In my car, the flexible riser really helped allow use of the rear position cupholder for the mount, and position the scanner at just the right height and angle, while still leaving room for a large travel mug of coffee!
If I was going to spend money on a new scanner mount today, it would be this
Mounting Solutions For Amateur Radio
or this
Car Floor Mount for Uniden GE Radio Shack Bearcat & Other Handheld Scanners & Radios