I saw 2 Vader's and a Fett yesterday at a Walmart... to me, the Fett looked like some sort of cheesy POTF2 diecast figure, I really wasn't impressed with it. I did pick up a Vader though, and was very impressed. If my computer at home hadn't crashed I would have taken pics of the Vader opened up...
It's really a lot better than I figured it would be - but talk about a lot of screws to remove to get it open. First there is a hard plastic shell over the figure itself that you have to unscrew - two screws for that. Then, Vader is on a plastic base that is screwed down to the main platform - there are four more screws you have to remove at that point. Finally, when that is done, you have Vader on another piece of plastic that is screwed into his feet - remove those two screws and he's finally free - that's 8 screws altogether.
Once he's open, WOW - something really cool about this figure. His helmet is removable and has a think piece of plastic covering over his bald head to keep it from chipping due to the metal head and metal helmet. The plastic is removable but after taking it off, I put it back on. He does have the original thick eyebrows.
As for articulation, you are looking at the neck, waist, shoulders and wrists. The legs don't move but he stands very well. This is a a great display piece and well worth the $15.00 in my opinion. I might get a few more like IG-88 when it comes available.