In my view there are five different solicitors professions in the UK. High street solicitors, goverment/local government/public body lawyers, BigLaw firm solicitors, in-house lawyers and solicitors practising in NewLaw firms such as Halebury.
The last three are the closest linked. A typical career progression might be to start off in BigLaw and move in-house a few years PQE and onto NewLaw later. The actual legal work can be very much the same but the other skills needed, especially as a lawyer becomes more senior, differ markedly. Mark Herrmann analyses this very well indeed in this blog. Essential reading for anyone thinking "should I stay or should I go" in-house.
Beyond pure legal skills, however, on what are senior in-house lawyers being judged? Here are the sorts of things I see: Does the lawyer set objective goals for people on her team? Does the lawyer serve as a visible mentor to others in the department? Does the lawyer publicly recognize (and share) the successes of people on the team? Does the lawyer have the courage to terminate unproductive relationships?