I do not like the focusing in M 600. It is not as smooth as Focomat Ic.
I do recommend a grain focuser.
Head sits comfortably on the negative carrier. No issues(atleast at first glance) with that. I will try to prints some 35mm tonight and see how it goes.
Focusing probably isn't as smooth as the Leica enlarger, but neither is the price as high as the Leica enlarger.
It is not bad, you get used to it. I found it smooth enough for me for 40 years. There may be minor adjustments that you could make, but I never did.
...but I did not pay much for Focomat Ic either, which in-fact costed me < 30 euros with lens.
i have never been disappointed by durst lensesbut don't know your 2nd either.
First image shows the alignment and second, the lens.
Yours look very snug, mine is raised a bit.
Funny, I'm at lunch looking at M600 operating instructions. I recently bought a M601 which is a quality portable enlarger. The M600 is at the top of a short list of even smaller, quality, MF enlargers.
I doubt there could be alignment issues given the 600 design. A grain focus device checking the corners would confirm alignment.
This is one of the most portable enlargers for enlarging MF 6x6 negs to 8x10 or smaller. If you routinely make bigger enlargements a M601 with taller column and larger baseboard is a better choice.
Nothing will be as smooth as the Leitz 1c but it can't enlarge 6x6 negs.