Yeah but if you add a tightbore and a better hop-up unit to an M16 :D
I dunno, before you buy an M16, hold a meter stick like a rifle, walk around your house a bit. It'll look really weird, but you would get a sense of what it's like, if my memory serves me correctly, an M16 is slightly longer than 1m.

You don't really need any upgrades for a while. Don't throw away good parts.

All that gun needs is a tightbore and metal hopup. I have one and completely stock it's out preforming everything else I have (with tightbores). Fires around (i'd guess didn't have the crony out at the field) 340-350fps. All I'm going to do to mine is add a tightbore. Also, M16's aren't for everyone. some people 6' tall find them too big but that being said, I'm about 5'6" and have zero issues using a full size M16.

I'm 6'0" and I find my M16 to be a good all-around size. But there are really two things to consider with an M16 versus your ability to use it: barrel length and stock length.

The barrel length makes it a bit unwieldy in really tight quarters, but it's fine in open space. That said, it can still be used effectively in close quarters if you tweak your shooting position. By tweak I mean either hold it with the stock over your shoulder or under. You can't use sights or (most) optics this way but if you get used to the gun you should be able to tell where it's going to hit.

As for the stock, the full stock on the M16 is up there with the longest stocks on any gun. Comparing it side by side with an SG552 and an AK, it has about 1 and 3 inches over them, respectively. You could always replace it with a retractable stock though, if you find it too long.

I didn't really say much about internal upgrades because I don't really know much about it and haven't done anything to mine yet, and because it seems to have been aptly covered by everyone who's posted before me.

You can always put a bag to carry the batteries on a sliding stock aswell.. this way you can still collapse the stock and carry the large battery on the side of it. Thats what I am doing on my M4

I'm 5'9" and have no problems carrying an M16A4 all day. I find M4s to be "compact." It all depends upon your personal preferences and what you find to be comfortable. As The Saint and others have already stated, all else being equal you won't find much difference between the two in performance. How *you* perform with either is a different matter.

at that cost you should look on ASC for a gun. you can find a way better deal.

Im 5 foot 7, and i have a m16a3 CAS version, i have no problem hadling it in a couple of tight corners, its got good accuracy, more than most guns, alredy a tightbore on it, just need a good new hop-up and some rubbers