Not sure how you can chase Plat Prem, since I'm one and have no idea what gave me that status.

Also not sure there is a huge difference between Plat Prem and Plat. I appear to get the same level of service from the hotels. The Plat Prem line can be a big help but is it worth driving all your business to Marriott? On average, so far, minimal day to day difference.

The downside of the other hotels is that FS Marriott is very consistent, the FS Hilton and Starwood seem to vary quite a bit. Seems they don't all have C-level lounges so it's a trade off in my mind.

But as pointed out, I'm going to Helsinki later this year and had to dump a pile of Diners Club points to get a Starwood property since there are no Marriotts.