Personally, I wouldn't eat dinner at either one - I'd get dinner at Flame Tree BBQ.
But if you really want one of those, this is what I would recommend: Join the Landry's Select Club. Both of those restaurants are Landry's restaurants, so you can use your card to get priority seating without an ADR. In fact, you actually get priority over people who do have ADRs. If you do this, you don't have to worry about trying to figure out an ADR time in advance, you just show up when you're ready. Club membership is $25, but you get a $25 credit to use on your first visit.