Can't make up my mind

[BBQBOY]

I have been debating which pistol should be my next purchase. It's between a Glock 21 or 17(but he grip is a littl big for my hands) M&P and XDm.
I've researched a lot an have been shooting pistols for several years. For me, it use to be an easier decision asto which pistol to buy but it's been about 6 years since I've bougt one. the last two I bought were an Od green Glock 23 and a HK USPc45. There is just so many nice variations now.
My concern for the XDm is the grip safety. I'm concerned if I have to "use it" then the grip safety could be a disadvantage for me. I've been shot at and held up before and I remember how my adrenaline raced. This is why the grip safety concerns me. I have read that it has to be squeezed just right to shoot, which at the range that's not an issue. The salesman today told me its easy and is not a type of safety that will hinder me in any way. That's the opposite opinion I have read. Anyway, the XDm felt great in hand and has a higher capacity over the M&P.
The M&P has really grown in me. When it first came out I thought it was ugly and looked gimmicky. Since researching more and reading on here more, the talk of this pistol has really turned my head to give it a second look. I don't have any. Once runs over this pistol but the capacity is a issue. I was going to get it in a .45 but may opt for the 9mm.
The Glock. I have not found a Gen4 G21, so I can not feel how the interchangeable straps may make a difference for me. Anyone's experience will be helpful in this area. I may end up buying the FDE version though,so, I will be forced to buy online, unless my shop will order one.
These won't be conceal carry weapons, by the way. These will be for home defense and range pistols. I guess they an concealed but I'll leave that job to by Titanium S&W revolver.
Ok, so, one of my largest questions are fittment of the gun to me. I watched a YouTube video the other day and in that video I heard something that I can honestly say I have never heard before. The person in the video spoke about how the pistol fits in your hand and lines up with your arm. That the slide, while pointing the pistol, should make a straight line as you point. I can honestly say that none of my pistols while pointed make a perfectly straight line is relation to my wrist and forearm.
Are these three pistols meant to point differently?
Edit: I just pointed my Glock and from what I can remember from holding the M&P and XDm, my Glock does seem to align more straight. At this point I'm not sure if I'm psyching myself out.
I tried to rent a. Our,e of these guns to shoot but I've been unsuccessful thus far.

[J_Dub_503]

Sounds like your way over-thinking this. I would suggest either a Glock (which you have experience with) or the M&P (Glock's largest competitor.) I don't care for how high the bore axis is on the XD's, it just feels unnatural when I tried to shoot it.

Choose one or the other and call it good. If you end up not liking it, resell it and buy something else.

[Denali]

I'd go with the G17(Gen3), a very well proven design. I'd warn you away from the G21, that is unless you're good with .45 ACP brass pinging off of your skull...

[BBQBOY]

Oh, that's not good about the 21. Now I remember reading something aout that. Why do you recommend the Gen3 17 over the Gen4? Is it because of the spring issue?

[MegademiC]

The mp45 is regarded as one of the best .45 acp out right now.

If you go 9mm - Id get glock. If you prefer m&p get that. If you go glock, the newest gen 4s should be ok,(not sure the start date - but thats what the gen4 problem thread led me to believe IIRC) or older gen 3s generally have less issues.

Both are very good guns. Pick one, stick to that series(if you buy multiple) and get good.

[jstyer]

The mp45 is regarded as the best .45 acp out right now.

Ummmm... Hyperbole much?

Hk45? Hk45c? I can think of many, many, shooters that would take the proven durability of the Hk way before the M&P45.

Which isn't to say I don't like it! But [I]BEST OUT[I], I think not.

[MegademiC]

Ummmm... Hyperbole much?

Hk45? Hk45c? I can think of many, many, shooters that would take the proven durability of the Hk way before the M&P45.

Which isn't to say I don't like it! But [I]BEST OUT[I], I think not.

Oops. I was tired when I wrote that. It should have said "one of the best" like I edited it above.

Yes, HK is probably the best out right now, but I dont even think about it since its not really in the same catagory as the ones mentioned in the OP and and also nearly 2x the cost.