IMHO it is best to have the status with multiple hotel chains and it is NOT worth being "loyal" to one specific brand. Last year I had 300+ hotel nights of which Marriott got 135, Hyatt 70, InterContinental 48, and Hilton 24. Do you really think that these hotel chains are loyal to you?

None of the chains are strong all over the world. I also like staying at IC's when travelling for fun because of RA benefits that far outweights Marriott Plat benefits. During the Hyatt's yearly FFN promotion I swing my all stays there.