I guess it all comes down to knowing your abilities (and limitations). For me, when the SHTF, the very last thing I'd want to be holding is a rifle built by ME!
But, ymmv.
-Cuz.
There has probably never been a better time for AR15 type rifles - there are several makers putting out very good rifles at decent prices, and more than likely if you shop around you can find one off the shelf with all the features you are looking for.
But the way I see it, if I do need my rifle in a SHTF scenario, who am
I going to trust more in building my rifle - me, or the guy at the factory 1000 miles away, where it is 4:53PM on a Friday afternoon and he just wants to get the Hell out of there because he's put together about 500 of these things this week. I don't mind spending hours paying attention to every little detail, because I enjoy it - it is just a job to the other guy, for the most part.
Sure, it might even cost me a little more to get a box of parts from BCM shipped to me and build it myself than to have BCM build it for me, but I am willing to spend the time to make sure my rifle is perfect when it is done.
Don't get me wrong, I have heard nothing but good things about BCM, and I am not saying that they are not very dedicated to putting out the best product they can. Though I have heard of other manufacturers, where the higher-ups say that they need to ship out "X" ammount of guns and get them to the stores no matter what, and deal with any issues that may arise through warranty.
Well, in a SHTF or TEOTWAWKI situation and your rifle goes Tango Uniform, what are you going to do, call a time out while you pack up your rifle and send it out for warranty repair? Will the company even still be around?
If something goes wrong with a rifle I put together I have no one to blame but myself. Even if it was something out of my control, like a parts breakage, I still have the tools, the know-how and enough spare parts to fix it myself, probably within minutes, instead of waiting perhaps weeks while it is sent back to the factory for repairs.
Sorry for a bit of a rambling post, but i am at work with nothing to do, so it is helping pass the time