.243 Winchester is an excellent cartridge, perfectly suitable for any North American game animal up to mule deer size and capable of fine accuracy in a good rifle. Cartridge case is the same as .308 Winchester/7.62NATO, just necked-down for the 6mm bullets, so magazines are not a problem. Unlike some other popular developments, .243 Win is readily available as a commercial cartridge so no home ammo manufacturing is required. Recoil is very mild.
If you enjoy it I think it's worth having. What's not to like?