Overall I'd probably give the edge to the Retina with the f2 Schneider lens. Bear in mind that you're dealing with cameras of two different eras (the earliest Retinas were built in the 1930s, the Konica S2 was in the 60s). The Retina was also a much higher-end camera than the S2 - they were meant to compete with Leicas and Zeiss Ikons and were priced accordingly when new. Today's pricing still indicates this difference- most S2s can be had for under $50. Retinas run from $100-300 or even more depending on condition, model and accessories.