Well I've been using the old system 4 Paterson 5 reel tanks for well over 25 years with no problems, using various developers including Rodinal & Xtol more recently. Secret is to get the developer poured in quickly, and use the locking ring as well particulary if less than 5 reels.

Have 2 of these 5 reel tanks, and numerous smaller sizes, also the largest which holds 7 or 8 35mm reels - I think it to risky putting all my films in this one and have never used it.

A good tip is to clean the reels by a prolonged soaking in Biological washing powder every so often, they load easier afterwards.