I never ever look for award seats - they're never available when you want them. All my miles go to upgrading int'l flights. Buying an ungradeable fare means you earn more miles for future upgrading purposes. Getting an award ticket means no miles earned.
Both good points. I understand that on some routes it can be really difficult to get C award seats as UA just doesn't make enough available on some routes. So if it's either spend money or spend miles to get a ticket (after getting status) - I guess I factor in spending miles first if it make reasonable $ sense.
Thanks for your input, FTer!