There are different things! The equivalent to BCG Gamma is not Mck Digital, but McK Advance Analytics!
(Just fyi, Mckinsey Digital is constituted by general consultants focused on digital practice, involved in the "strategic part" and no particular coding or analytics).
Now talking about Advance Analytics, it does differ from a general consultant in many things: core job, skills needed, profiles recruited... however, the quality standars and competitiveness is the same -it´s the same firm with the same values, after all-.
Lifestyle can be different since they tend to travel less -and not even always- and have slightly better work-life balance.
Good thing is that they are growing massively now in Europe, and your profile could really fit.
Hope it helps!