There are times when the rack rate is high and you'll want the poker room rate, but IME that is the exception rather than the rule. In the past few trips I have made over the past few years, the best rate I could get online was the same as, cheaper than, or at worst within a couple bucks of the poker rate (which is not all that cheap to begin with, it was $129 the last time I got it), so I usually just do that, particularly if there is a chance I'll want to go sightseeing, visit with friends, or do other things that might interfere with my poker playing time.
YMMV. But to get the poker rate you generally have to play 6+ hours of 20/40+ while clocked in with your card, then ask the floor to set it up for you, and hope that they're not too busy/lazy to do it. I can't recall if you have to ask them to do each day separately (I think that was CAZ, not Commerce) or if they will set up your whole stay (long hours and/or a decent tip might make this more likely). At least that was my experience several years ago when I got one. As mentioned, the past few trips I've just booked it online at a similar rate.
Here is a post I made about it in 2011:
https://forumserver.twoplustwo.com/1...l#post28475048