Don't look back, its a relatively inexpensive shooter and always turns a few heads. I personally own a 14.5" but the difference to 16" will be neglegable to your everyday target shooter. the 10.5" barrels are definitely a wicked looking unit, and horribly awesome loud !! but range becomes very limited and a bit of a draw back for us shooters who like to poke holes a few hundred out
You may also wasn't to look at the difference between DI ( direct impingement ) vs gas piston - one works by directly applying spent gas to the bolt carrier, racking it back while the other drives a small piston to accomplish the same task. Piston/Gas debates will be futile at best so be sure to do your research ! I don't want to give you my style choice as its nothing more than a personal preference. I would suggest also getting on youtube or some AR specific forums - there is a wealth of knowledge regarding very specific questions you may have.
You will generally see three + variance of all AR builds.
Base ( basic generic parts like, stock, handgaurd, grip and likely no sights)
MOE *or alike ( Generally equipped with Mgapul like products including upgraded stock, handgard, grip, mags, etc etc. )
Tactical ( usually includes the magpul like products as well as a quad rail and possibly iron sights )
keep in mind that the internals or these units are identical ( in the case of variances )
Another term you will see floating around is "Milspec" or commercial. This will refer to the tolerances, threading and size of some specific parts. generally a Mill spec gun will runs premium but you will be guaranteed that parts will fit down the road. That being said, there is nothing wrong with a commercial AR - I have one of each and to be honest, haven't run into a scenario where something hasn't been interchangeable ( aside from millspec stock on commercial buffer tube )