Probably very dead, considering that Tuvixing is a biological process and Data isn't biological.
If we're just thinking personality combination, I'd think he would just be a milder, hyper-intelligent version of Worf in many ways, as I think Worf's thoughts would fill in a lot of Data's questions. I think this combined being would probably be a much better father to Alexander, though.
Worf would be having a most unpleasant time. Data's not biological, unlike Tuvok and Neelix, and I can't imagine Klingon biology is very appreciative of having techno-widgets rammed into it.