Okay, specific response: The age/maturity factor question is pointless, because you are asking a question of general averages and expecting to apply it to a specific situation, i.e. any particular two people forming a relationship. Everyone is an individual, and I've met countless immature males AND females of any age, and occasionally meet some impressively wise young people, also of either sex.
This whole "women maturing faster" concept, is more accurately aimed at boys and girls, by the way. Again, it is a generalization, not a rule. There are far more important factors to consider in a potential romantic partner.

Love is all that matters.

Imho, the brain and its contents are 95% of it.

Society, dictates otherwise. Fuck Society.

I think it honestly doesn't matter as long as the couple is happy. My cousin and her husband have an almost 30 year age gap between them. The man is older but it seems to work for them despite her still being immature and not knowing what the hell she wants (she still has a very child-like brain (in my opinion) due to childhood trauma and not getting to actually be a kid). So I think it depends on the individuals. I personally wouldn't date anyone in their 30's (since I'm only 19) because I am still exploring life and I feel like at the point most men probably want to settle down whereas I want to continue to explore, unless I did feel serious about them but we aren't in the same stepping stones in life and I feel like that could cause it not to work. I personally want to be with someone my own age or close to it because we are in the same stage of life, figuring shit out. Though, having an older man does help in that. He's got more of an idea about life and all the bullshit that comes with it, but it is also weird dating someone around my biological uncle and mother's age.

Every couple is different. No generalization about age should be applied to something so deeply personal. I've seen examples of each combination work and of each combination fail.

Based on my own experience, I have always looked young for my age. I used to get carded into my 40s. For that reason I always attracted younger guys. After my first divorce at 39 I dated younger and older. After my 2nd divorce at 44, I met someone 8 yrs younger and that relationship lasted 10 years. After that I met someone 25 years younger when I got sick and he supported me during that tough period, remarried his wife and daughter recently but is a friend still. Now I have dated guys closer to my age-some I have trouble to relating to-others no. Age is irrelavant to me-its who the person is.

In my opinion age is just a number.
It is the personal will of the involved individuals that counts. If they feel comfortable together, age is completely irrelevant.
Of course considering that people that are closer in age may be closer in their desires too, thus making a match much more likely, exceptions to this are by far not that rare.

With humans , the word "should" rarely works.

In love, the age factor is all over the map, with every possible combination happening all around us. Some work - some don't, just like any other qualifying feature.

I think you have to take it case by case. Being of similar mindset and having compatible long term goals is more important.

Personally, if I'm not getting along well with someone, it must be THEIR immaturity that's to blame. Yeah, yeah, that's the ticket!

Maturity level... but unable to match certain specific experiences important to your development because the partner was not born takes away.... some fun. At this stage in my life an "Old Soul" with a lot of fire left... will be to my liking. Mind you on my teens I was already an old soul. I got nothing to prove or to be ridiculous on purpose... My Ego is Relaxed and Tamed.

Age is just a number...
Could have a 20 y.o. be more mature than 40 y.o.

It can't be a set standard. Some people are old when they are in their 20's and some are young into their 90's.

This is an individual decision mutually agreed by a couple. I cannot tell anyone who to love. I prefer someone close in age as there is a media thing... and I choose not to live in headphones.

Not that it matters, funnily enough, I date younger men for the most part and both my sons girlfriends are a few years older than them as well. I date younger, only because one- I don’t look my age, two- it’s who I’m attracted to 3- because of my age, it’s not like I’m looking for someone to coparent with, just someone to have fun with. If I was still in the marrying & having babies stage of life...a few years in either direction is the ideal

I have seen both ways quite successful but I am older and like younger women that submit to the authority of the man but not be his slave be his helper

It is ALWAYS dependent on the individuals. There is never a universal answer. Some people prefer immaturity or maturity AND everyone matures at a different rate regardless of statistical frequency.

Uh, Why is this even relevant?

Would a man aged 50 want to date a woman 1.5 times his age? That depends on the reason(s) of attraction. I think that a man would probably date someone younger than himself but if the woman looks young enough to be his daughter they both may feel uncomfortable about it, however, if they are both happy then others who are not so happy will find something to gripe about. The same may hold true for women. I think that it is a matter for the adults concerned. The imposition of restrictions upon consenting adults, in terms of an age gap between them is nothing other than a form of control.

The rule is the younger person should be no less than half the older person's age plus 7.

While it is true that females mature faster than males, I feel that it only applies up to a certain point in one's maturity. When adulthood is reached it tends to level out.
Once a person is matured, then it becomes one of compatibility, and age is no longer an issue.
When I first began dating I preferred males that were about 5 years my senior, but now it's become more about life experience, and intelligent thought.