I'm in love with my 35/2. It's not just "sharp" and it's not "contrasty" , it separates
tones exceptionally well. It's physically a gem. It's well worth $400-500, certainly is in Leica league. Makes me want a 50 1.4 Canon, despite my Nokton.
I don't know about CV 35 optical performance (I have a 25 and a Nokton 50) but CV is really just Cosina, after all, nothing like Canon/Pentax/real Nikon build quality.
Canon 35/2 is less than half the size of CV 35/1.7, fwiw.
It's true that Leica builds gems, and my long-gone 35 'chron was physically finer than my Canon (which equals anything else by Canon or Nikon)...but I don't think it was optically better.
Leica's biggest drawback is if Kim's looking for LTM: There's no LTM 35 Summicron, and if there was it'd be worth $1500.
A 35 2.8 Elmar LTM would be sweet if one could be found in excellent condition, but of course it'd cost $650+ and would be a stop slower than the Canon (which in my experience is quite effective at f2).