FF is at version 11. FF add-ons are gradually breaking compatibility with the older 3.6.25 Gecko as FF moves on, but Lunascape continues to use old, outdated Gecko code . I would recommend upgrading Lunascape to a newer version of Gecko to retain compatibility. I have to say that of all of the web browsers, Lunascape is easily the best overall for low/mid end machines because it is just so light on resources. It uses a small fraction of the memory Chrome and Opera use.
A few other features that would be nice to see... How about the paste and search/paste and go options in the right click context menu for the URL bar and search bars? All other browsers have them and they are helpful. Also, Lunascape seems to have some problems with Java. For example, when I try to post a comment on the forums of tomshardware.com, sometimes clicking a java link does nothing. Two examples of this is when I click "show comment" to show comments hidden for a low rating, it does nothing and sometimes clicking "post comment" does nothing. For not using sites like that, Lunascape is still great, but for tomshardware.com I must use a different browser and I use that site many times a day. At least it's not as bad as Opera, which does the same thing, but is a lot slower about doing nothing and sucks up RAM as greedily as a congressman who found a gold mine in the backyard of one of their vacation homes.
I'm not sure if Lunascape supports multi-core and/or hyper-threaded acceleration by using more than one core/thread to do work much faster or not, but I don't think it does and would like to see this implemented. The only other major browser that also hasn't done this yet is FF, but Mozilla plans on solving that. I'd hate to see my favorite web browser left behind in performance due to faulty Java and being restricted to using only one core at a time and a decreasing percentage of the FF add-ons.
I'm forced to have several browsers and often times more than one browser open at the same time just because of the trade-offs that each browser represents. I need FF (or more accurately, I use Palemoon, optimized FF, but retains 100% FF compatibility) for add-on compatibility with certain add-ons that I sometimes need to use and I switch between using Palemoon and Comodo Dragon (security/privacy optimized Google Chromium) for other uses, usually using Dragon more for work that uses multiple CPU intensive tabs or requires extra security.
Just solving the add-on compatibility problem by using a more recent Gecko engine would mean that I don't need Palemoon as anything more than a back up browser and fixing the Java problem would make Palemoon completely unnecessary. Anything more (paste and go/search, multi CPU core/thread utilization, etc) would just be icing on the cake and is less important.