exactly what i'm thinking. I'm leaning towards the biogon 21 f2.8 because it is somewhere in the middle and price is a decent value. Not too leaning towards the voigtlander 21 f1.8 because of the size and fixed lens hood, the f1.8 would be great though.. hard decision.
i guess it depends on the framing and situation. I got some decent ones with my 15mm voigt but that is really sometimes hard to handle hahaha, so I'm eyeing a 21mm that should be more practical.