The Westin Harbour Hassle Hotel, as it is know, is good but there are only a few suites. Most are Jr suites (one per floor) but these are really just oversized rooms, not really suites.

Sheraton Centre has at least 2 real 1 bedroom suites per floor.

The trick to upgrading is to register for short stays, as no hotel wants to tie up a potential revenue loss on a suite for longer term stays. One night is ideal, two is generally OK, much more is pushing your luck. Well, that is my experience.