Same here. I've never had residue from just using Saphir Reno but have found it using Saphir neutral wax. In a perfect world neutral would make sense if you really like the color/patina of your shoes and want to "lock it in" but I think the beauty of Kudu is the irregularity and I'd rather just condition when necessary and just enjoy watching them patina naturally. Strikes me as the type of leather that the more you wear the better they look.
Point is, between TTownMD and dddreess I'm starting to realize I need to add some kudu into my life.
Do you find it any more comfortable than calf?
I don't find this particular Kudu wears significantly different than calf. I did find the one pair I have in my possession to be rather comfortable, but I attributed that to how well the MH71 Last fits my feet. It was a bit snug initially which is generally a good sign but rather comfortable not to long after I started wearing them. I always wear mine three times for about an hour each time before wearing them for any long period of time. This seems to help me anyway. So although there is a texture to the leather it still feels more like regular calf and not as pliable as Scotch Grain or Country Calf.