...and it only gets worse.
Have you seen the interior of the new C-Class?
The difference between the "tablet" that Merc uses in it's entry level cars and what the OP/Stinger did is how the driver interacts with it.
Merc OEM uses the comand wheel to interact with the system, whereas tablet solution uses touch. The wheel allows linear and predictable input, easier for muscle memory and remembering shortcuts/processes, thus allowing an experienced user to interface with the system with minimal distraction.
The tablet, while it has way more software potential, relies completely on touch input. The main issue with touch input in an automotive application is that it has no tactile or spacial element. So if you wanted to change the radio station or do most actions available on screen at any given point you have to look away from the road in order to know where you hand should go to complete an action, as opposed to the OEM solution which has the advantage of tactile feedback and muscle memory.
The placement of the "tablet"/screens in most MY2007+ in Mercs is no coincidence. The high-up placement allows for use of peripheral vision when completing an action on the media interface, keeping your focus on the road. Having this placement with the tactile controls allows for that.
: If you install one of these tablets, make sure that it is in line with you instrument cluster to allow for safer/easier use. Double check the laws on automotive interfaces where you live to make sure your install wont get you a ticket.
Imho just save up the money and get a Chinese or aftermarket head unit. Yes it does not have the advantage of all the apps, however it is 100% street legal. If you go the Chinese HU route you can even get an OEM look-alike, which you can find several extensive threads documenting the different models if you do a quick search.