3 years has allready gone since I got my tripod.
I did never got any Sachtler CF 100L or ENG 2 CF. I ended up with a 'cheap', second hand Vinten Pozi-loc 3773-3. This tripod has about the same specification as Sachtler CF 100L. I have no idea how it compare to the Sachtler in rigidity or longevity, but I know I have happy with my purchase. It works just as expected.
The Burzynsky head has been permanent mounted into the 100mm bowl, with a long bolt and hex nut. It is 3,5kg complete with tripod, head and AS-style clamp, just the same weight as my old Berlebach report 2012 tripod with RRS BH55 ball head, but better in every aspect.
600mm/4 is no problem for the tripod, but the ergonomic of the ball head is on it's limit with such heavy lens and narrow field of view. The Burzynski head is even working very well with almost no load, like with my Fujifilm X100S, very contrary to the BH55 ball head that need some more load for working well. So this is a real allround tripod, and has been used much more than I had thought.
I have been so happy with this tripod, so after about an year, I found another second hand, even cheaper, Vinten Pozi-loc 3776-3. This tripod is 3 section (like Sachtler ENG 2 CF), and has been fitted with the Sachtler DV6SB fluid head for telephoto usage. This is of course a much heavier combination than the first tripod.
Thanks for all inputs.