I was one against the whole 6 months, then married stance.  I understand now that it doesn't take that long to know if a woman is wifey material and if you're going to marry her or not,  It's actually much easier now with dating modern women. 
They make it easy to get a clear view picture about them, to see if they are already a wife.
I'm starting to look at women in a whole new lens, I was always using a lens as such, but the lens now has become very clear.   
1.  She has to already be a wife
2.  Masculine energy will be present after the 2 month - 4 month mark, see if she has any of that energy stored up in her, and how often does she displays it towards others and especially towards me
3.  Kevin said something that stuck and it's true (we call it the honeymoon stage wearing off) but looking at it from another angle, it's just a man now understanding what else does a woman have to offer, bring to the table, besides sex, looks.  Can she be great in other rooms besides the bedroom after all the great convo wears out on the phone/through texting.  
4.  Do you feel at peace with her, can she bring peace to your life or do you find yourself consistently helping her out in her situations, bad days, moody, upset with work etc.  Is she at peace and content with her life.   
5.  Does she listens to you, (I do this often), I'll ask after month 1 or 2, for her to send me a picture, and I'll wait to see how long it takes for her to do it. It's not the picture that I'm more wanting, it's her commitment of her following directions, respecting my request and her willingness/corporation  of her to do it.  
I'll even ask for her to stop at the store and pick me up some gummy worms, all this done month 1-2, after the sparks have died down, in a sense.
6.  Bring her around family, see how she gets along with friends and family, etc.  
Until then, if she's not a wife, she will get smutted out until I get tired or vice versa, when she sees the situation isn't going anywhere, and then I'll probably hit her with the "it was cool, but I think I'ma fall back" or I plain won't even waste her time.
There more things but I'll stop there and state that, it truly doesn't take a long time to get married, looking back on my relationships, I prolonged it because those ladies that I was involved with weren't necessary wives, from a standpoint on what I want in a wife, that's why shyt carried on and on in some cases.  
Dudes know if they got themselves a gem/wife and dudes know how to make the right move, I'm talking about dudes that thinks with their brain and uses wisdom.  Know how to vet a woman properly.  
I believe now, it doesn't take a man long to know what he wants, if that man wants to get married.  I will admit, I was on the whole, I need to know her for 2 years etc.  Nah.  
Not saying this is right or wrong, but I understand KS's point and understand how things were done back in the day with our grandparents and great-grandparents