They are the same size like the Stargate and Arrow figures, so who knows what kind of cross-overs I will come up with!
Let me introduce them to you in detail:
Kirk and Khan at a console:

You can't take the wrench from his hands though, but he comes with a second pair of hands, as Spock does:

Isn't this pretty?

The backside isn't bad either:

They don't have moveable knees, so instead they come with a second pair of legs. It actually says "Kirk" and "Spock" on them, but I guess I can switch them as I please:

So if you switch the Kirk legs, he can hang in the air doing his kick:


And Spock can kneel:

I like that as with joints you never get them to kneel like that!
This is what Spock originally looked like:


We also have a second head and more hands:

And tricorders - one open, one closed:

And here's one for my friends who are slashers:

