I think whether or not you are disappointed depends on what your expectations are. This isn't a Disney hotel with Disney soaps and Mickey wake-up call, but personally for $20 I wouldn't mind. If this is your "once in a lifetime" trip, than possibly you would be dissappointed, but if you've been to WDW before than it is a GREAT deal.
We just stayed at the Marriott in June using 2 free weekend night vouchers from Marriott. The rooms were large and we had a balcony with a pool view. The staff was exceptional - way more friendly than we have experienced at even WDW resorts. The CM said "she had the honor of checking us in." Way to make you feel special. They also have a managers reception at night with free drinks, nachos and popcorn. The pool wasn't themed, but it was decent. My kids had a blast there. But, we aren't picky and were happy to be splashing around in the cool water.
They were replacing some floor tiles in the back hallway to the elevator, but we didn't mind that. Although some might. They had a couple cones with caution tape up around it.
It is very close to DTD and may be walkable, depending on who is in your party. The bus transportation to the parks is decent - I think they come every half hour. Although we didn't use these. It sure beats the other off-property shuttles.
If the $20 rate was available for my time frame, I would jump at the chance and not look back. Unfortunately we are planning to go the last week of November. You will be paying for about 5 nights at the Marriott for the price of 1 night at CBR! Think about all the fun stuff you can do with the savings, or if you are practical, just think of the savings!
I guess my point is, it depends on your expectations. You can have a very magical time here.
Maggie