It is our “go-to” piece of labware and we rely upon it heavily.
Never used the other machines you mention, but one major difference is that the 901 has only piston pumps. I recall a few people on this board who were not happy with all the calibration and/or pump problems with the dedicated titration peristaltic pumps. If you’re feeling flush, I would say spring for an extra pump so you can have 2 different titrants always loaded.
It will titrate va distillations, and there is a must nitrogen method for ‘fan’ that we use a lot. There is also an ‘rs’ method but I have never put much stock in it (think it’s based on the layne method?) so I use and the pill for rs checks.
Solid piece of equipment, but it is really just a simple machine that does acid-base and potentiometric titrations. It is still subject to GIGO, so poor calibration, sample prep or distillation will make it a fancy paperweight.