its 4 feet long(breaks down to two pieces, both two feet long)
and wieghs 3 pounds
Personally, I would never use one of those as a main weapon. I'll show you mine and even with all its features, it still not my main weapon simply because there is not enough targets even in a large scenario.
Picture of mine
Most launchers are large and require you to put down your marker, pull out the launcher, usually have a few player covering you, take aim, fire, reload, put back, and pickup your marker. Its easy to say it a small launcher that can be pulled out quickly, shot and reloaded quickly, and put back quickly but when it comes time to do so, its a lot harder. Most places play that gun hits count, that launcher (though small compared to some) can be a nice target. Those launchers are more like shoot and toss lauchers because its not worth the effort recharge and reload them in battle.
On mine, I've eliminated the need to put down my marker, have others for cover fire, and long recharge and reload speeds. It can be loaded, aired up, and fired while shooting. It does have some great benifits and is great for those times you need a launcher but most of the time it just sits there.