Now, to try Vanguard and SCE. How did they turn out?
I've not read SCE, but I thought Vanguard was great.
It's got a great cast of interesting characters, almost entirely novel-only characters. If you like TOS, it provides a really interesting picture of what was going on in places where Kirk and the Enterprise were not -- except for a couple of "guest appearances." I enjoyed the way Vanguard storylines filled in some of the blanks behind the TOS episodes and movies, while telling their own story at the same time.