Diversity is definitely the biggest pitfall when using jump pilot flying to build time. If I was looking at someone's logbook and saw that they made other flights to deliberately train and retain skills that you don't use when skydiving, like IFR flight plans, flights with CFI's, XCs, etc. vs. a jumper dumper that had done nothing but skydiving flights for the last 2 years, I would likely lean much more towards the candidate that kept their other skills fresh, all other factors being equal.

The other flight experience that I have found is almost totally worthless to some groups is CAP flying... some people I have talked to have even said that they know people who even see it as a negative, but I could never confirm. Its a real shame because my local area has lots of mountains and awful weather most of the winter so going through their aircrew and mountain flying school was some of the best training I have ever had, and no one cares or believes me because CAP has such a bad rep...