not accurate, the serpent conversion only requires an AE center pivot. ($3?).
i consider this an improvement, not a negative. (the serpent pivot costs $12 and doesn't work as well as the AE part)
other than that, you need 2 standoffs and damper tubes if starting from a s120L.
Well on the op thread you list some other items also in this post
http://www.rctech.net/forum/9791083-post171.html
Folks lets be clear here I'm not out on a which hunt here just providing info so that the person can make an informed decision. Also if you care to look in the op thread Paul assured me over a year ago that he would change the website and informe distributors so that new customers would be aware of the additional items needed for the OP105 kit; has'nt happened.