Matt,
I don't want to be negative, so I'll just be straight forward. The book is available in the Kindle version for $0.99 — pretty inexpensive, and if I thought it might be somewhat interesting, I would have risked 99 cents. Then I noticed it was only 67 pages long; seems mighty thin to cover even the basics. So I downloaded the free preview. To be honest, this didn't pique my interest.
I did see a longer sample on Google, which made me less enthusiastic.
So here is some quick feedback using your section on Clothing Layers as an example (the stove and water purification sections weren't much more informative either)…
First you don't really explain how layers work and why they are important. There is a paragraph about "Cotton kills," which isn't actually true in many situations. You throw in a lot of stuff like "Clo" but don't explain what that means. Then you touch on the value of wind shirts, which is followed by a paragraph on rain jackets where you state they are not breathable, but eliminate the need for a wind shirt — all very confusing and not factual. Seems like there is a lot of opinion not backed by facts.
The sections I read need a lot of proofreading for grammar, sentence structure, spelling, etc. Many acronyms the reader may not be familiar with (e.g., AT, CDT, PCT). If the reader knows what Clo and down fill specs are, they probably don't need your book, but you toss those terms around without explaining what they mean.
It feels like you just threw this together.
So…
The book doesn't need editing or reviews; you need to start over.
My son is a backpacker, and definitely not UL or whatever label we want to put on it. If he expressed an interest and wanted advice on an UL gear book, I would probably steer him towards Skurka's book, not your's. But don't give up if you want to become a writer.
Determine who your target audience is. Then read some of the well-known writers of the gear genre. Colin Fletcher, Andrew Skurka (his first and I think only book), Chris Townsend, and Mike Cleland (for an alternative style) come to mind. Study them. What do they do well? What do they miss the mark on (if they do)? Do they establish their credibility as experts in the field, so their insights are to be valued?
Then revisit your book.