With only a few days, I would spend a little more for the location. That said, either the Ren or the IRS will get you to all the tourist locations with just a little extra time and work.

268 is an awfully high rate for the Marriott, which is indeed an excellent location. If a Marriott is a must, I'd probably spend the 179 for the IRS. To be perfectly honest, if the 79 is more in the OP's price range, I'd probably look away from Marriott toward a hotel that is closer to the center at a rate closer to that price, or even consider an airbnb.