Indeed I noticed that booking a studio suite outright was not a lot more expensive than booking the basic room so my upgrade was appreciated, but its cash value was not as high as what some other hotels give. It makes it tempting to just book the studio suite. However I am wondering if doing so will preclude an upgrade to a higher category room?

If I had not been upgraded to a suite I would be less tempted to return soon given alternatives in the city. Sounds like I got somewhat lucky...