Oh I don't think Shell Valley is a bad deal. The thing is, and it's true with SO many replicas, is that any given build can vary widely, even wildly, from one to the other. That is a primary reason why some folks prefer complete rollers, like an SPF, or a McDonalds hamburger. Always consistent! Some folks like to build their own burger, or buy one built "their way".
Some of them home built burgers are terrific, others are a disaster. Choose wisely as you go forth, grass hopper.
Then you have the gourmet burgers, thats a whole 'nother can of worms right there.
I found brobehr's comment to be especially on target...