Andy,
I would start out by defining the segments in terms of weight. Traditional, Light, UL, SUL, etc. This would be base-wight. I would not express your opinion as to the best method. Allow the reader to figure out which is best for him. Also comment on why base-weight is the proper method to use so we can compare "apples to apples." Then in each section place the gear in each category. For example stoves (e.g., white gas, canister, alcohol, tabs, wood, etc.). You will also need to discuss how a heavier stove might be appropriate in special conditions. You will also need to treat winter as a special category. If as a hiker I am just not going to buy into a trail runners, what other light weight options are there. And if I am going to reduce most of my gear weight, but just cannot get over leather boots, which ones are the best? Lots of gear lists are helpful. Fletcher used gear lists with weights over 40 years ago.
1- How geeky do I get? Is it reasonable to talk about R-values of sleeping pads, the water absorption rates of different fibers, and the nuances of LED technology?
Absolutely. Get very detailed. Allow the reader to pick the gear based on the features and benefits of materials, construction, weight, longevity, etc. Numbers are your friends :) !!!!!!
Also lots of pictures and diagrams. Show the reader what the gear looks like and how it is used.
2- How can I defend this book against inevitable attempts to dismiss it as a lightweight book?
I don't think you will need to, if all the options are presented properly. The reader will be able to consider all the options, and make his/her own decision based on the material you provide. You may get more people to go really light, but those who opt not too, should be able to use your book as a valuable resource. Three different people may pick Light, UL, and SUL, based on their own needs. Take a look at the last edition of Complete Walker, Rawlins sprinkled in a lot of UL stuff, even mentioning Jardine several times. Here is where I would be cautious… will you come across as a credible expert on non-UL gear. Do you have enough experience using it; does your analysis logically entice the reader to try lighter options? 99.9% of the readers will never attempt one of your adventures, so you need to make sure that what you present makes sense to the average hiker. Fletcher was known for his epic trips, but his Walker often discussed the gear he used on short trips, even simple overnights. Appeal to what your reader will be using their gear for. If I am a recreational runner, I am not going to use the training methods of the world record marathoner, but if I can take pieces of the training that are applicable to me, I will use them. I am not going to train 150 miles per week.
3- Given the changes in the publishing industry, am I correct in taking the self-publishing route, and printing a pre-edition that will be out for about 3 months before the full edition is ready?
Your profession is "Adventurer." So I think this needs to be an income producing effort, not a social good for the UL community. So you need to consider the options. Traditional publishing will get you into more "markets" and you will have publisher advertising, exposure, etc… however unless you have a track-record name like Fletcher, no one is going to invest in a niche-market. Plus, you will earn less money per book; so it depends upon how many copies you sell. I would go the self-publishing route. Kindle eBook is probably going to be your most profitable approach in this day and age. I would not pre-edition it!! On Amazon, you can allow readers to see small portions before purchasing. Will I buy your book? Maybe. If it presents lots of information in a single source, that I can apply to my personal needs, yes. And I prefer it to be available on Amazon in Kindle format.
4- What are the major weaknesses of other lightweight books? How can I avoid them.
They promote UL as the only way. Do not preach "I am the way and the truth and the life. No one comes to the Father except through me." Many BPing authors present too few options, and much of what is presented is opinion, not detailed information (the geek factor). This is true even with traditional books. Fletcher sold more copies than anyone else, because his books were large and full of lots of objective information.
I do have a concern that you are rushing this to market, and it might not be as good as it could be. I write technical manuals. Last year I wrote a 50,000 word training guide and needed to do zero research, as the information was in my wheel-house as a subject matter expert. It took me 6 months to complete it. This manual was not sold, it was part of training my company provides to our clients and is proprietary to our training delivery. The success of our training is dependent upon the skill of the trainer, but the manual had to be good.
Even with the self publishing effort, I highly recommend that you hire a good copy-editor. That person will help you more than you know. You want this book to stand the test of time, with only technological advances as the variable for future editions. Since Fletcher has stood the test of time, I would read Walker 1, and Walker 4 very carefully to see what worked, and what did not. You do not want to emulate him, but dissect the most successful backpacking book of all time. If you limit your audience, you limit your income. If your book appeals to most of the Backpacker.com, BPL.com, WhiteBlaze.com, etc. audience, then you will be more successful. Also your potential readers may never venture into a backpacking message board. Remember there is no right way to hike, there are many ways to hike.


