The Travelocity statement credits have their highest return in $400 increments. You can redeem whatever amount you want. The highest value (4%) is achieved at these increments. So yes you can stack.

What I really like about this is the lack of restrictions. Trying to find a Saver award when you actually want to fly is not easy. SPG and Amex MR is only better when you luck out and find a saver award somewhere for a first class ticket that is ridiculously over-priced to begin with.

At $100k spend, I get $4,000 in Travelocity credit. I'd rather spend $1,000 on an economy ticket to China and spend the other $3,000 on whatever. I know some people "must" fly in first class though. So to each his own. I'd rather keep the $3,000 in credit and also earn the miles on an econ ticket.

On hotels, you are limited to SPG brands. I can pick any hotel on Travelocity. Just way more flexibility to travel where and when I want to.