Las Vegas - Flyback promos?

Wondering if anyone can provide some feedback on how these Flyback promo's work and if they are worth it. We're looking to take advantage of MGM's $59/night with $300 flyback promo.

The fine print talks about being subject to terms and conditions like needing to book with the travel agency noted on the certificate. Booking with a specific travel agency seems to be a big unknown to me. The other conditions sound pretty reasonable.

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Whoops. Did a Google search and pulled up this related thread on a Mandalay Bay Flyback promo.
http://www.flyertalk.com/forum/showthread.php?t=724326

The T&Cs on the ones I've looked at in the past (not specifically MGM's) seemed pretty restrictive. It might be slightly advantageous in really great cases where you can't find a good fare otherwise. I wouldn't get too jazzed over it. Better to find a good gambling freeroll or other offer.