We all know him. Maybe he's a friend, or your brother in law, or that guy at the range. Maybe he's the "expert" on youtube. He's the Gearhead. It seems like he's always got the latest and greatest gear and he can't wait to roll you in his opinion like a sugar cookie. He'll tell you every minute detail of the latest gizmo's design and manufacturing process. He'll tell you that because he trains with *insert high speed / low drag badass group here*, he just had to have this thing to keep up. Sometimes he'll look at whatever it is you're using and explain why it sucks, how your performance suffers because of it, and what he's got to solve your "problem."
Don't fall for it.
Chances are, the Gearhead is compensating for some other pitfall by drowning himself in new purchases. You do not have to buy into every craze that comes along. It goes for equipment, it goes for training, and it goes for techniques. Think your way through. Ask questions. Learn.
For example: On my AR, I use a pistol grip with interchangeable palm and finger swells because I have big hands and it prevents me from over indexing the trigger.
I purchased a particular piece of equipment to address two issues I have. That does not mean you should immediately go out and spend $40 on a Magpul MIAD grip. Yes, the MIAD is a good piece of kit. But if you don't need it, wouldn't that money be better spent on ammo or a training class? Don't fall into the financial pitfall of keeping up with the Gearhead.
I'm also not big on buying the first of anything that comes out. Often, manufacturers are in a hurry to release that new product, and sometimes they still have some issues to work out. How many times have you seen the phrase, "Gen2 model with the following improvements" in an advertisement or review? Let the Gearhead work out the bugs for you, and then spend the smart money on the upgraded version- or snatch up the used first model cheap!
Y'know. Unless you're independently wealthy, a lotto winner, or just have to be "that guy"...

Please read the following article in a full-blown screaming rage voice...
I am so sick and tired of this argument, I can't even explain. It hurts my head every time I see another Youtube video, blog post, or Facebook discussion dedicated to "finally ending the debate" as to which of these two firearms is better.
STOP IT!
Here's the bottom line: There is a reason BOTH of these rifles still exist! There is a reason both of these guns are sold by the millions worldwide!
Stop arguing the "combat effectiveness" of either of these rifles! Any AK sold in the US has been modified to be 922R compliant- it is no longer genuine surplus! Stop arguing that the AR has "been proven" by the US Military- they don't use semi-autos! (I see you in the back- you go ahead and tell me the Air Force does. Then go choke yourself!)
Here is the only single true fact in this entire debate- Whether you choose an AR or whether you choose an AK, YOU ARE DOING IT BASED SOLELY ON YOUR OPINION!!!
And you know what? That's OK. It's ok to have an opinion based on nothing more than your preference. So do us all a favor and just admit that you like one better and that's why you chose it. Because, so help me, the next time I see this debate I am posting a link to this article!