San-Francisco-based industrial designer Anson Cheung, a former partner at Bould Design, has been in the ID game for over a decade. On his Design Things blog, he shares a wealth of hard-won knowledge and advice from the field, and all of it's worth reading.
For starters, perhaps you've heard that in general, a UI/UX gig will pay more than an ID gig. Cheung dug into the stats to confirm it. "At every level I looked at," he writes, "the difference is almost $20,000, which is substantial."