I just used it myself and EHOTEL20 took actually more than $20 off, since it took it from the base price ($80 to $60) and this made the taxes and fees drop from $10.29 to $9.99...
Need to book more, but I have better (personal) coupons for that.
Please keep in mind that these can only be used today (Nov 9th) except for NOV10
Their coupons always take part of the hotel taxes off. It's just not taking the taxes off if the rate is less than $20.