Superia 1600 is very, very impressive if you expose it properly. It doesn't tolerate much overexposure, and underexposure produces very thin shadows - which in turn appear really grainy. There is no real 1600 speed alternative if you want a fast color negative.

Some s1600 shots: http://hakkarainen.kuvat.fi/kuvat/20...0-01+-+Sitsit/