... I bought multiple watches from him, all good experiences. But when buying any preowned watch, be sure to get photos in advance of all boxes and papers (inner box, outer box, etc.) that come with the watch, so you can actually see everything you'll supposedly get before you get it.
I haven’t bought anything from Markus but I’ve been to one of his offices which is professionally run.A freind of mine deals with him regularly and only has good things to say