I was thinking hands down airline status, but do see pitbrian's points.
All things considered, I would still go with airline status. For those of us who like to make last minute travel plans, the ability to make and change plans fee free is one of the most valuable things for me being 1k. The SWUs and CR1s are up there as well.
SPG Plat is great, but realistically I don't use, receive, or value the benefits that much. Basically, I value the free room most and the Plat benefits are marginal, though appreciated!