The Hotel Theodore is really just the new name for the Scottsdale Mondrian (http://www.yelp.com/biz/scottsdale-mondrian-scottsdale). One day they got bought out and simply changed the name.
A year ago we had a bad experience at the Scottsdale Mondrian (the worst part was being woken up two of the three nights by loud partying at 4 a.m.). We complained, and they eventually gave us a voucher for a free night. Not exactly what we wanted, but we decided to take a chance and use the voucher when we were down for spring training this March.
Our return visit under the "Hotel Theodore" banner was marginally better. The rooms are still horribly dated (the rooms are painted white on the top half of the walls and black on the bottom, with funky furnishings to match) and slightly run-down with cheap bed sheets, but the pool area is nice, and at least our fellow guests were quiet this time. OK for a one night stay, but we won't be back.
UPDATE: They've re-opened yet again, this time as The Saguaro (http://www.yelp.com/biz/the-saguaro-scottsdale-3). We haven't stayed there under the new name/ownership, but I can see from the pictures that they've at least painted the rooms bright colors (thankfully banishing the weird black and white from before).