I've owned a Rollei 2.8C/Xenotar for more than 20 years and have put probably 250 rolls of film through it. It's a wonderfully sharp lens, makes almost bleedingly sharp, contrasty images at f/8. At f/22 it's still sharp and takes on a smoothness I can't easily describe. Having almost never used an aperture wider than f/5.6, I can't attest to lens qualities or "distortions". I can't compare it to a Planar of similar vintage, and I'm sure that the Planar has wonderful qualities of its own. Either way, you can't go wrong. You're choosing between a Mercedes and a BMW.