Unless you use it only for Marriott charges and their air partners, IMHO it's just not a good card for converting points into FF miles - for example, 70,000 points (at a buck a point) for 25,000 FF miles on many airlines. It's worse for some of the foreign-based airlines.

Let's say your 250,000 MR points came from everyday CC charges (excluding Marriott and air partners spending). If I put 250K on my Citibank AA MC, I could keep 120K for plane tickets and convert the remainder to 260K HH points. That would give me 6 nights at a top-end Hilton (soon to be 175K) and leave me with 85K HH points - almost half way to another 6 night award. It's even better if you can put it on a Starwood Amex.