Lenses compared:
CV12, CV15, ZM18, 21 Lux, ZM21/2.8, 21 SEM, ZM25, 28 Cron, CV35/1.2 II, ZM35, Canon 35/2 LTM, RX1's 35/2 Sonnar, ZM35C, FE35, CV40, 50 Lux ASPH, Canon 50/1.4 LTM, CV50/1.5 LTM, ZM50C, ZM50P, FE55, CV75/1.8, ZM85/4, 90 Summarit.
Most lenses performed better or more 'naturally' on the M9. The widest decent non-native lens were the CV12 and 15 with very similar edge performance on both cameras, though both also have very strong vignetting and color shift. The CV35/1.2 II was the widest and least problematic. The 21 Lux also wasn't too bad, but lags in the outer zone until around f/5.6. The FE55 bests the other 50s for across frame consistency, though the Lux showed higher central performance while the ZM50P was decent, but seemingly a bit lower on the resolution scale. Everything longer than 50 was pretty much a draw, as would be expected...