It's very good, rock solid so far and a piece of cake to fit (nearly).
I found that the screws supplied to fit it to the TTR cradle were too short. Well two of them were. The ones that go straight from the cradle to the bracket are fine but the ones that have to go through the back of the bracket that mounts the unit to the bars were too short
I had to dig out some alternative longer ones I had lying about. Other than that the fitting was easy.
The only other observation I would make is that the key they supply to fit the screw at the top of the cradle which locks down the slider is a bit naff and I could see it getting chewed up very easily.
I replaced it with a screw that had a allen key type head as it seems somewhat more sturdy and less likely to chew up.