I'm finally done exploring the wastes and finished the main storyline yesterday. It's okay apart from the plot holes, the lack of logic and the ending. It could also use a bit more freedom. For some reason I liked the uh, follow the bot scene.
Crashes got really bad for me at some point when I explored the wastelands. Take out enemies and try to loot the bodies, fast travel, save via the menu - all of that had a really high chance to throw me back to the desktop with the message box. Luckily at some point I noticed something that reduced the number of crashes almost down to zero. I always have FRAPS running and have it display the FPS. I noticed that before a crash is going to happen the frame rate is going drop a bit (and it usually dropped after fights). When that happened quicksave/quickload made it go up to normal again and I could loot, travel or save without problems. It's annoying but better than a CTD. I have no solution for the occasional 3 minutes loading times, though. When I decided to follow the main quest again the problem didn't show up. Not sure why. There might be a relation to me using the A3-21's Plasma Rifle during the wasteland exploring but that's really speculation.
Sounds bad but all in all, it's still an awesome game.