the Fujifilm S3 taught me many lessons
it has an outstanding jpg engine, which is a good thing as its RAW files are huge
here is a link http://forums.dpreview.com/forums/read.asp?forum=1020&message=14464709 from Moshe Vainer to a useful analysis of why 14 bit capture can make for better 8 bit jpgs than 12 bit capture
NEF & DNG files each vary depending on the conversion engine
the Leica digital M files are written as DNG and even the M9 writes a smaller compressed file than an OOC S3 RAF file (!)
whether the M9's uncompressed DNGs are significantly better than its compressed ones is a subject that will be briefly explored here
Raw conversion is a complex subject with many options, some of which I have explored in a limited fashion
here are some comparison tests I made
YMMV