Albie is more experienced than I by a long shot. That said, I brought a friend in recently for a meet and greet with our CP. His answer was that it looks bad if you just bank a few thousand hours and then sit on your butt at a desk job waiting for a call. A flying job, any flying job, would show your desire to fly. CFI work would probably be adequate.

I think that the recency of experience gets you the interview. Having to answer the panel once you get there that you bought 100 hrs in a 152 might not go over as well as if you took a paying flying job.

I would also imagine that regional time would be looked upon as high quality to an interviewer. If you're willing to make a low wage at a 121 carrier you're kind of a known quantity.

This is all just me thinking out loud. Others, feel free to shoot my rationale full of holes.