I still use the single and 3 spiral Paterson II tanks. They work well, and don't leak (much) unless the grey lid is getting old. Have inherited several new tanks, but they all use more chems than my Paterson II tanks. Only problem I have with them, is they don't load well if the film is damaged by lets say the angry winding action of a Russian rangefinder camera. The newer tanks with there ball bearing action are easier to load in that respect. From memory my single reel Patterson II use about 245cc of chem for a 35mm film, where as my other tanks don't work with less than 300cc (i think from memory). Also I use these tanks for inversion, and have never found the need to bash them too hard, just a couple of taps does the job nicely.
Hope that helps,
Dan