In reply to dl_wraith: Thanks, all, for your input thus far. The general consensus I'm feeling here is that exposure to differing disciplines is a positive and desirable thing and that certain skills may not translate to an equal gain between differing types of climbing.
So far my own experiments with indoor bouldering and outdoor traversing/bouldering is certainly improving my ability on verts/slabs both indoors and outdoors. I'm finding my foot placements more accurate and my ability to spot potential moves improving. Not to mention the obvious general fitness gains.
As I gain more experience we'll see where this takes me.
As an aside, I'm also finding that exposure to many different climbers is also helping. My own close group of friends climb differently to the members I met from the KMC who climb very different again to some of the people I've met from UKC or at indoor walls. It seems the more I'm exposed to the more likely I'm able to fin some technique that works for me, working past my own inherent limitations.
I did think that the old adage of 'jack of all trades, master of none' may apply here but I suppose that sort of thing wouldn't kick in until you got reasonably good at all-round climbing anyway.
Oh, and yeah, at least one of my group is a little intimidated by the outdoors because "there's no colours to show you where to go". I jokingly offered to take some chalk and mark out some holds for him