Weapons difference (shot per second)

[gozo1985]

i want to know whats the difference between some weapons... why does some suck ? why does some rock?

here an example:
tornado summoner (2.222) - rox
machine gun (2.500) - sucks

is it the range(700 vs 888) or the shots per second? also it seems like the machine gun is not creeping well. you damage some creeps close to death while other players or creeps get them with weapons with a slower shot but more damage.

is it right that every weapon with many shots per second suck?
also in mid games i prefer poison magic instead of flamer not becouse its cheaper... or less range... i buy it becouse of the shots per second.

poison:
If you port to an enemy the first shot takes lets say 15% damage.
flamer
If you port to an enemy the first shot takes around 2% damage.
so you start with a small advatage in a even fight (same HP skills no creep and so on)

i know there are some other cases but imho weapons with many shots per second suck.