Let me add that one of the advantages of a custom map designed for competition might be:
Everyone gets about the same starting position and there aren't any relatively bad starting positions for anyone.
The team's have equal sides and preferably symmetrical sides (to make sure it's fair).
On some maps, you're guaranteed not to be wedged in between two opponents.
Sadly, many folks won't take the two or three minutes required to download a custom Sins map and to add it to their game (it's very very easy). When I think about what I used to do to play custom capture-the-flag maps for Unreal Tournament (1999) back in the day when I was on dialup, it's kinda sad. The custom maps would auto-download but I often had to wait 5 or even 10 minutes for some maps. I also went to the trouble of figuring out what new maps my favorite custom CTF server was hosting and downloaded them in the background when I wasn't playing. It's kinda sad that I was eagerly willing to go through all that hassle to play on custom maps and today's gamers aren't interested in a simple two minute procedure. (You can easily download and add a custom Sins map in two minutes if you know what you're doing.) (1) Download the .zip file of the map. (2) Unzip it. (3) Open your main Sins game folder. (4) Put the MapName.galaxy file into the Galaxy folder (where all your maps are stored). (5) Put the .tga file (lke a jpeg, if there is one) into the Textures folder. Done. You don't even need to close the game.