The Zeiss Planar and Schneider Xenotar are considered equal in quality with some feeling the Xenotar may be slightly better. The Tessar and Xenar are considered decent lenses but not on the same level as the Planar and Xenotar, but close when stopped down to f8-11. Whether you get a f2.8 or f3.5 is really your personal choice and depends on the light levels you will be shooting in if handheld.