Was just in the same exact situation staying at IHG properties and I chose the Chase Sapphire Reserve. It's just hard to go wrong with the flexibility unless you need a specific amount of IHG points for a specific redemption. You can usually buy IHG points for great prices though with their pretty common points purchase bonuses.

The only reason I used the IHG card recently at IHG properties was for the Priceless Promotion (or whatever it's called) where you have to use a Mastercard.