The 959's AWD was a very expensive system, so probably considered by Porsche not cost effective in the 964/993 911's of the time. Ferrari as fas as I know, only now started to incorporate active diferential tech with the F430 and its only for the rear axl, not AWD. As to the type of auto tranny, I guess Porsche was always more focused on manuals and also took the road of the torque converters applied to sportcars since they started with the innovative Sportomatic auto offerred already in the early 911's, and then pioneering the introduction into mainstream cars the modern computerised torque converter autos with their Tiptronic, the best of its class. Now that sequentials are almost mainstream they seem to be coming out with the best of the best in sequentials, a double-clutch sequential, while Ferrari is still with the 6-speed single clutch that is slower than BMW's sequential (6 and 7 speed).