Thanks for the feed back!!
Looks like 13-17mm is the favoured "middle man". While I won't be buying additional eye pieces for a while, I want to make sure I can build a solid working set over time, I'm aiming for a range like: 6, 8, 12, 17, 20/22.
So I guess I should be getting either the 12 or 17mm to start the set. I might have thought that the 12mm would be too much mag for the average sky, but that is more a feeling than backed by any empirical evidence.
By that logic I guess the choice could be narrowed down to getting either the 12mm Delos (better eye relief) or the 17mm Nagler?