As been mentioned already, both types have there place and advantages, guess it comes down to exactly what you intend to use it for most. Myself was always leaning towards a quad for speed and ease of hauling, but the best thing that ever happened in that regard was when I lucked out and picked up a few year old HPX 4X4 Gator with only 450 hours in need of a bit of TLC. Paid $4K and ever since Deerland delivered it, that little bugger has been an almost daily runner except when it's really cold for December and January. I seem to keep finding new things to use it all the time. Even made some special hitches so I can use it to push or pull my smaller grain augers upto and including 50 footer 8 inch Sakundiak to position them over a bin, no pin required. I even have started putting up more square baled hay, as it's nice to be able to sneak around with it with ten bales or so rather than bucking mud and tearing things up to put out round bales. Box fits twelve five gallon pails nicely for feeding grain out on pasture, and the list goes on. Have never regretted buying it and would be seriously in a bind if I had to be without it again
Now I do have cattle and that is mostly what it is used for, but it also is so dam handy for anything simply being able to pack stuff around like my portable compressor, tools, sacks of seed, whatever, stuff you just can't do with a quad. I was looking for a quad when I ended up with the Gator, and can't say enough how for me and what I do, there is no question it was the machine I needed. As for quads, I gotta say go Honda, though sounds like most I know with newer Polaris are liking them a lot too.
Yes it is more cumbersome in tight quarters, found out almost the hard way it don't like water over about 6 inches deep for any great distance, don't have the high speed of a quad. Is also a fair bit heavier as well. Will not fit in a pickup box either. Have two trailers I haul it on, one is an car hauler for which I have two little short ramps made from Marsden matting and once you run it up to the front, have a chain that hooks to the front hitch, lock a boomer and she's tied down in 15 seconds. Second trailer is a old tilting skidoo one, which is handy when you are moving equipment around, as the Gator easily can pull its own wagon behind it when the need arises.
I'm over six feet and well over 200#, no question the side by sides are easier to mount and more comfortable to drive for me. Especially if I am experiencing lower back trouble and pain...not having to lift my leg to swing it over the seat is a physical benefit as well.
Was looking to see if I had a picture I took last spring for a forum member about how many bales it could pack( 13 in this one) and I found a few more of a modification I made to the shifter cable in the console between the seats. The cable was kinked when I bought it, so I straightened it out best I could, it all worked good till got cold last winter, then it started hanging up and wanting to kink again, so I rigged a support at the end of the sheath. Works perfectly now, never an issue since.