We are looking to put our km6500 out to pasture. I have read the many posts regarding light production printers with great interest - its great to read facts. The c5100s & C651ex have similar price point (tbc?), & it appears specifications. Could anybody please suggest which is a better machine and why? thanks heaps! I believe there is difference with toner & fuser assembly, is the registration as good? is the c5100s a c651ex with a facelift? Or is the 651 actually a better machine? Very little 'real' info is in the public domain.... All thoughtful comments respected, cheers!