I think the other reviewers were blinded by the train and the tech nomads.  I wish I was.  This book was painful for me to read.  I read for the characters mainly.  The post-Apocalypse setting appeals to my inner 80s child also.  Milan hosed the characters badly here.
This is another title where the author breaks with a LOT of character traits in the various characters.  JB Dix "why use 3 words when you can use 2?"  Oh, except in this book where I think he has more idle chatter than any other 10 previous books added together.  JB is also rather unimpressive with his weapon knowledge here which is the major defining skill his character has.  He knew about the test but was far too impressed by the other armorer and his attitude and comments just didn't add up with his normal personality.
Mildred appears to have gained crazy amounts of weight.  Repeatedly she is mentioned as fat throughout this book (our star Author Andy Boot apparently read this one because he makes the same mistake in the next book).  Mildred is described as being very much in shape having spent a lot of time hiking.  (Milan - take note that not all black women look like Aunt Jemima you twit).
Kristy was OK as were Jak and Doc.  Something actually bugged me about Doc but I can't put my finger on it.  Maybe it was just the general miasma of crappy story line around him.
Ryan had a number of things that were out of character for him also.  Mainly around his attitude and perception of right and wrong.  He tries to do right where he can but puts his friends before moral issues.  He would kill someone based on what they might do and wouldn't think twice about it if the situation called for it.  Here he all of a sudden has some moral qualms in situations where he has never had them before.  (Again, Andy .... read more than one book back if you start writing a series...or at least Andy's editors... you made the same mistakes in Ritual Chill that were in this book).
Lastly.... Ewoks?  Seriously?  Star Wars fans thought they were a cop out exceeded only by Jar-Jar and yet you had to go down that route huh?  Not only that but you gave them en exceptionally cutsie name.  Maybe you could have pulled it off without the other screw ups.  It was a bit excessive to introduce ewoks and the tech nomads group in the same book though.  Whats next?  Stickies that talk like Jar-Jar?
The tech nomads have some good but semi-limited potential.  (Remember that outlands happens in the future so things can't occur that would change that setting).   Big points for them.  I would like to see them more and from the other reviews other people would too.  The train setting was also very good but unfortunately it blew another howitzer sized hole in the ratings.  This general finds this pristine train in a redoubt and takes it out and builds an empire.  Not a single one of the companions ever thought to consider finding the redoubt where it came from??? Even if the train was the primary treasure there, the repair facilities, armory, etc etc would have been a wet dream for the group.
I'm going with a 3.  You can't gut core components of the characters - the sole constant from book to book and expect to get good ratings.
You guys should take 4 volunteers from the forum each time a new title comes out.  Have them read it as a prize and submit feedback - then edit it.  Hell you wouldn't even have to pay them and you'd get people that love the characters and the setting.  Clearly all you do on some of these books is a spellcheck and grammar check in Word or whatever.  It is a shame when a book like this one with some good potential can be fixed so easily but isn't because of bad editing.