I've got one of Nathan's tubes, and very nice it is too. I live in fear of breaking it, however.
For those with the conical type, if you are as dumb as me, reading the graduations can be a little tricky towards the bottom of the tube.I did this graphic which I find very useful. Print off and stick on the shed wall ...
Ha! Uber-Tube, I like it!
Just to confuse the issue I think I'd prefer the Nathan tube as with only a little dropout it appears it would be easier to see how much.
I do find tiny globs of oil stick to the sides of the tube if the reaction isn't complete and that flicking the tube does little to free them.