I'm rather new to this too so take this for what it's worth....
I have a beer gun and my brewing buddy has just the regular tap set-up. He always brings bottles of beer over when we are brewing at my house. All he does is put a tube on the end of the spigot and fills the bottles from the bottom up and then caps them. Works great and the beers have good carbonation.
I went ahead and bought the whole Beer Gun system. It fills bottles fine also. I decided on the extra equipment because I want to enter my beers in competitions and I want to bottle beers that I want to age.
I will have to wait and see how well my decision works out. I haven't had the system long enough to enter these beers in any comps and I am just now getting some bottles into storage.
So, I dunno if any of that helps but it is the best I got..

PFC BN Army - Tactical Hop Command
Fermenting - Kolsch, Blonde Ale
Kegged: Flanders Brown
Aging: Brown Lambic, Chocolate Porter
President and Chief Bottle Washer - HopRunner Brewing~Ross