mushy101: Oh of course, and after redeeming themselves with max payne 3 (which runs beautifully on a number of pc's played upon) I have every every confidence that they can.
F4LL0UT: Ridiculous loading times (which are obfuscated through cutscenes which are in return unskippable most of the time) for ridiculously small locations and *okay* graphics. Also I've run into insane graphical glitches in multiplayer which made walls invisible - and partially allowed me to see enemies through them. Yup, technical masterpiece - they can't possibly screw up the most ambitious sandbox game yet when they can't even deal well with an oldschool third person shooter.
And from what I've seen concerning the switching of characters - it VERY much reminds me of early 3D squad games like Hidden & Dangerous - with the difference that there I would be in control of the whole situation, not be prompted to switch characters whenever the writers want me to. :P
Compare Max payne 3 port to Gta4, or the absolute mess that was the pc port of bully. Yeah, despite your point, I have confidence they can deliver.
They also ported LA Noire too, and apart from the engine limitation that locked it to 30fps ran a damn sight better then the horror stories before. Let's not also forget the Hardocp IQ review of Max payne 3 showing it running great on a range of hardware, among a lot of other reports from sites such as eurogamer, techreport, etc.
Your case was bad, but it's pc gaming man, every machine is different. Every machine reacts differently.