The 100W Compact is a nice simple little boiler, we have found them reliable in service. Once the spark generator was shielded they have been OK.
It is regettably true the now discontinued/replaced 100W combi and system were unreliable.
The 300 range has not been imported into the UK since February, so you won't be getting one of these. The 200 system has to be on a sealed system and you have to cap off the internal diverter valve etc. Quite unnecessarily complicated for the application.
PS: BB wouldn't know the 300 has been ditched because the Viessmann web site is out of date. He isn't going to hear from within the trade either, because he's not in it.
