It hasn't let me down. It sticks firmly to the base plate, doesn't wobble and once you get the hang of it, is easy to adjust. If I were to make one criticism it would be that given the portrait aspect of the Satmap, the height of the mount can cause it to intrude into your forward view through the windscreen, but provided you take that into account when locating the mounting plate it should not be a serious inconvenience.
This car mount is excellent quality, it is easy to adjust and once in place is very sturdy. You do have to use the mount that comes with it, this is basically a rear cover for the Satmap device but with an extra moulded fitting that slots onto the bracket. It is nice to be able to follow your route on an OS map as you are driving.
As a person who likes maps and planning my own route I use SatMap rather than a SatNav. This product is well made and fits easily onto the SatMap by replacing the battery cover. The sucker is strong and adheres to the windscreen well and gives a good degree of movement allowing the SatMap to be positioned conveniently.
This is a very solid suction type mount. I use it in my 4x4 and it holds the Satmap very securely and, so far, has not dropped off like my Garmin mount is prone to do after a bout of strong sunshine on the windscreen. If you want to mount your Satmap securely in your car then this is the mount to use.