Crowne Plaza is a hit-or-miss brand. Some hotels are older properties badly in need of renovation, some are well modernized, and some are in transition (meaning they're hit-or-miss room by room). You really need to read reviews sites to know what you're getting before picking a CP.
That said, even the worst CP I've stayed at was worth more than $49 to me. I routinely make the certificates worth several times the credit card's annual fee.