I believe that the only differences between all those tools is toughness and longevity. I have a cheap Nashbar chain tool that looks identical and works fine, but it will most likely not survive long if it was used daily. Most cheap bike tools are like that, they work fine but won't last long under heavy use. So as a home mechanic with 3 bikes I see no reason in spending large bucks on expensive tools. If you run any kind of shop or even maintain a lot of bikes for friends and family then the better tools make sense.

Adam