Subject says it, basically. Really just about to hit the buy button for this, but only concern is that the original titles especially depend on a joystick rather than keyboard or mouse. I'll be using KB/mouse; will I be at a huge disadvantage?

The older ones do work but are indeed a bit clunky with M&K... the UI is fine (it is actually almost entirely designed around cursors+ENTER), but the flight part not so much

A lot depends on what you're used to for flight sims. I played the first X game back when it first came out (1999) using a mouse and keyboard, and I found that it worked really well. I had tried it on a joystick at that time, but didn't like the feel.

I've been playing these games again recently, and didn't even consider using a controller or joystick, but my control came right back as soon as I had on hands on the M&K. So mouse and keyboard are definitely viable if that is your preference.

It is worth noting, though, that by the time of X I had been a pure PC gamer for many years and hadn't used a joystick regularly since the '80s (Atari 2600). If you are both a PC and console gamer, or if you're used to using joysticks on PC, you might well find that control scheme preferable.

I started X: BtF last night and the initial thoughts about mouse and keyboard are that they seem quite reasonable. I've not gotten into any space combat yet though (not even got any weapons right now).

Additionally, I've also set up GlovePIE to accept some voice commands and that works really well. First time I've ever used voice recognition with a game.

X:BtF feels better with a joystick but works very well with mouse and keyboard too. From X2 on you'll use your mouse 90% of time anyway, because there's so much stuff to do that you can't do with the joystick.