Those are all cool boards, but they are dramatically more expensive 3-10x and harder to get started with. I've used BASIC Stamp as well and so am not "making this up either". When I was first getting started with physical computing stuff, I tried to use BASIC Stamp and ran into quite a large number of difficulties. While the BASIC language is relatively straightforward, the installation/first run story is full of bad pitfalls. And BASIC Stamp also forces you to know a lot more about [edit: PIC not AVR] architecture in order to accomplish the basic things. Again, these obstacles aren't that big for programmers/more experienced EE-types, but for regular people they are deal breakers.