Compression gear is obviously a big market these days and there have been numerous studies done which have proven that the garments improve performance and aid recovery. If you go to the websites of any of the brands you've mentioned you'll see links to this sort of thing.
As well as links to studies, you'll also see that the way the companies make their products differ, so as with other running kit, it might come down to which ones your friends recommend, which ones you've seen good reviews for etc.
I guess with many things when it comes to physiology (training, diet, supplements etc) just how much benefit you'll get will vary from person to person.
Compression socks seem to be getting overtaken in popularity by the calf guards which are made from the same material as the tights and shorts.
Some companies have specific recovery ranges, others have products that can be used for exercise and recovery.