I tried some SN100C from AIM... On only one array. It flowed well on the chips but did not like the finish on the SOT23's on the board. I did not have enough arrays to mess around, so we switched it over to SAC305 and had no issues. I'm guessing with some oven recipe adjustment it would have wetted well.
In the very near future we'll be running some boards using a SnCuCo paste. I haven't seen anything in the forums about SnCuCo, but it's properties are very similar to SN100C (SnCuNi).
We're running SnCuCo in our Pb-free wave and our Wave Master Chris is very happy with it.
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=42439)