I never USED TO change brake or clutch oil...its a pain and takes a bit of time. Now I just open the cover, suck out the old, refill, suck it out again, refill and then I am good to go. I figure changing 95% of the fluid to clean & new frequently is easier. Plus I use this for lots of other things...my trailer brake reservoir, my jeep, pulling out a little extra oil if I overfill lawn tractor or dirt bike. They are practically self cleaning and I now have about 3 of them. I have one for non-critical use - tractor oil, large brake reservoirs, 1 for pretty clean and one for very clean that I ensure I keep super sanitized. Don't forget...you suck up the dirty stuff and then push it into waste container, then you suck up again, etc. You are never really putting clean fluid in it and then into your bike so cleaning is minimal or not required.
Never done my own fork rubuild, but I've used this syringe for almost everything else. Bleeding magura clutch, bleeding my Scott's damper, used it full of Rotella T as an assembly lube applicator when doing my bottom end rebuild. Only issue is the rubber seal pops off the plunger at times and you have to fish it out and reset it. Not a big deal and kind of to be expected with a long term use tool seeing many different oils.
The rubber plunger swells up after many forks. It would be nice if you could just buy that as the rest is fine. Or, make it so the rubber keeps its size. No matter, I use a little plumbers grease on it and can get it to work just enough to draw the excess oil when doing a fork rebuild. Have a couple extras in case the plunger will not slide into the syringe.
I've used this many times over the last several years and it's still performing well. The rubber plunger can get stiff in the cylinder. If this happens, a small dab of o-ring grease brings things back into order.
Fork oil is pretty hard on the rubber plunger on the syringe. It is nice to have a replacement available so i don't have to by the whole tool again when they wear out. It works great and is at a great price. I keep a spare as well.