I'm sure you'll be happy to know that the Gateway book is basely largely on the GEnie/Sunbane data.
I've just spent some time comparing UWPs out of the Gateway book to my database of GEnie info, and except for some tweaking, it's the same.
So, if Second Survey is only going to be a rehash of the broken, they yes, I'd agree, we don't need it, and if like that, I won't buy it.
I'm somewhat disappointed that Gateway to Destiny's worlds are based on it.