Here are some quotes from nikon users:I have seen my share of professional and/or accomplished photographers giving poor advice. ("yeah, sonny, get one of them cameras with large pixels, those will have less noise"). I have no idea if the people you quote give good advice.
" I would look for a used D700, D3, or D3s. The D800 files are going to be way too big for your needs. The D4 is somewhat overpriced for what you are going to need."
"D3s is the leader for low light, D4 is a piece of junk. D800 is crap unless you're in a studio. Wouldn't touch a canon unless 5DMrkIII"
" Best wedding camera on the market today is the D3s. The best value wedding camera on the market today is the D700."
" I agree with Brady, D3s is a beautiful camera. Shooting with 2 32GB CF cards with one for immediate backup is a great way to shoot a wedding with confidence! D800 is a body geared towards the landscape/commercial world but not for weddings. D4 was a dud."
OK, here are the sites of some of those quoted --
LOL...I find it funny that as opposed to hearing the other side of the fence recommending lower mp'ed bodies for weddings in your mind = obviously bad advice. Why is it so hard to accept that if you don't need to shoot to print 40x60 or larger a lower mp camera is bad?? What I find even funnier is that in a standard photography forum (not nikon or canon), you see many nikon users telling younger photogs that the 5d3 is a great idea if your upgrading to FF and are not invested in glass? File size does matter if you shoot 2000 images or more per event you shoot.
According to my shooting habits the highest amount of files I get while shooting is near 200. Developing them in DPP and some PP in CS2 (old but suits my needs), piece by piece. Due to an old and slow PC I don't even shoot full res. mRAW is way enough for now. So MPs really count. IQ wise as well, if you aim at mostly high ISOs and available light. So for me to go far beyond the current MP count of my 5D3 in a next body cycle would be a loss. As the 5D3 is a great low light tool at a (still) decent price. Especially if your amateur budget is not apt for an 1Dx. I'd prefer a split: 5Dx ("revolutionary" 22 -24MP sensor, decent ultra high ISOs, 50-51k "native", 102 and 204k extended, 0.5-1 stop improvement in RAW in comparison to the 5D3) 5Ds (new high MP sensor, ISOs 50-25kmax, ultra high DR)