I was in a camera store yesterday and got my hands on the 58 AF-1 and the build quality isn't any better than that of the FL-50, if you were wondering. Still, the extra power and twin flash ability is appealing.
OT: Also tried an E-510 and it felt nice but definitely not a replacement for my E-1.
Thanks for the feedback, personally I am very intrigued by the 3D fill flash; something I could do on my E-300 but not on my E-1.