You can own this as your only 50, and I know a couple of guys that do, but I feel the 50 Planar or Leica is better as an only one lens solution (which is why I went for both). I am now up to four 50mm lenses but I love my 50’s!
If you learn how to use your Sonnar on your camera it will become quick and easy to focus the way it needs to be focused for sharp results at 1.5, and that is where the magic of the lens happens..wide open.