Having finished it now I have to say it was wonderful - instantly one of my favourite Trek novels. I know its popular but I wasn't blown away by Immortal Coil. This built upon it brilliantly.
Most of what I'd have to say has already been said, but I would like to add that I read it that Data's mother (and Lal's grandmother) is still out there and Data may need her help to save Lal.
And also, if Data has all of Soongs memories, how different is that to B4 having Datas ? Could we see a Soong 2.0 at some point ?