"Not the most amazing reward" - well, I guess we'll agree to disagree. Sand Shaper is an amazing PrC, and I was honestly expecting you to hide it behind a whole chain of prerequisite research (the Drift Magic feat seems necessary for example - or perhaps Earth Spell?).
I thought about doing that, and if you guys had researched it earlier I might have done it, but as it another research chain for a PrC that would get little screentime anyway felt like it would be forgotten again thus making it a narrative dead end.