Anything comes up, let me know

Well, I used Wombat for years when I worked at Bear Stearns. Wombat is just like any other data vendors. It's all about cost and benefit. You have to know what you are doing, and make right decisions about hardware/software architecture.
By the way, we are going to release FAST support in the next version of QWFIX trading system. Then we will have a complete portfolio of trading and market data solution.
FAST is a new standard for market data. It has its strength and weakness. In my opinion standard doesn't matter as long as we have one, so that everybody can only use one universal standard and compete on performance and usability.