Horrible. Horrible horrible.
For some inexplicable reason...Steam began auto-updating both M2TW and RTW (even though I turned them off), and now my mods and save-games have been deleted.
RTW, I'm not worried about. All I was playing with was player1's bug-fixer glitch and some extra fixes I added, that's easy to restore. M2TW, I lost my English campaign. I had dominated Europe, Africa, America, and was en route back to the Middle East and Russia to fight the Timurids and Mongols. So it deleted the retrofit mod (with GUAM) and everything with it.
Edit: It seems the updates were to switch the MP servers from Gamespy to Steam. Additionally, M2TW also bundled all of the Kingdoms campaigns into M2 itself, getting rid of the old launcher and using a Steam launcher. So while it's possible to go to M2, click play, and get a list of the Kingdoms campaigns and the vanilla one, there is no way to install Kingdoms based mods because there's no Kingdoms folder. I tried installing retrofit, but the installation path couldn't find Kingdoms. At all. IE there's no way to play Kingdoms based mods for M2TW anymore. Additionally, the siege AI for RTW is also bugged.