I've had great luck and love my Hercules 32 meg GF2 MX, but it's now getting sadly out of date. Lots other cards are faster and have more memory. If the choice is MX or GTS, then I'd go with a 64 meg GTS card. Personally, I'm looking at the Ultras right now. Not really that much more than the GTS and lots faster.
My 3D Prophet 2 MX has default clock speeds of 176/166, so it has those measly 6ns memories, but it OC's quite well, as can be seen from the signature. It can take AGP bus speed of 89MHz at 2x, using a Pentium II 350 on Asus P2B rev 1.0.
Those down under prices are awful. No wonder so many Aussies overclock. You have to to run a decent computer without costing a complete fortune. Glad I'm a bloody "Yank" and can get cheap computer components.