That's a pretty open-ended question...

I don't know about TG, but the KL C-class bonus for long-haul is now only 50%, not 100%. Only intra-Europe do you still get the 100% C bonus. As a FB Gold you will also get 75% status bonus though. So total number of award miles for most of your itinerary will be 225%, while status miles will be 150%.

The main benefit for me in choosing *A over SkyTeam is the quality of (some of) the airlines. You get to fly the likes of SQ and NH on *A, whereas with ST the best you can probably do is AF or CO long-haul. It of course also depends on where you want to go: if you need a lot of flights within Asia, Canada or Latin America then *A is an easy choice over ST. In the US SkyTeam might have better choices, whereas in Europe it's probably a wash.

It also depends on what you want to use your award miles for, what your other flying patterns are, where you want to start, etc.