Migration assistant is taking days and it keeps adding estimated time

I set up Migration Assistant to move data between my wife's old MacBook Pro (2010) to a new 15 inch Retina MBP. It's been 21 hours since I started the process, and the time estimate keeps getting bigger. It started by telling me it would take 31 hours, at some points it revised the estimate to 75 hours, and even went up to 108. This morning it is saying 49 hours...
I am using the FW800 to Thunderbolt adaptor that came with the MBP.
I've been through this process before with other Macs, and I never ever experienced such ridiculously long times. I don't think there is more than 200GB of data that I am moving.

Is this normal? Should I wait TWO MORE DAYS to be able to use this machine?

Should I cancel and start over? If I stop the process and start it again, will it "credit" the amount of hours and data it has already moved? Is there any chance relaunching the process will speed it up?

thanks for any help

Pablo
Brooklyn NY