If you ever plan on entering your brews in a competition, they'd need to be in a bottle.
When I switched to kegging my brews, I put my bottling bucket away and haven't touched it since. When I need a couple of bottles for a comp, or I want to bring some to a party (bottles, growlers, etc.) and don't feel like schlepping my keg across town and setting it up, I'll use the Beergun like prj28. Great piece of equipment to have if you keg but still like to put it in a bottle from time to time.