I was able to stick my head inside the M series with white - WOW! We are running a 1640, and the lease is up so the timing is perfect! they've gone to a single print head configuration and done away with the wiper blades. The print head is smaller, with a consumable "cleaning belt" that now cleans the print heads automatically. The cleaning belt has also reduced the excess ink container by half! (i hate changing that!) new optical sensors for reading clear media, and a new and improved winding system. The UV lamp belt that consistantly hits the top of our cover is now smaller and has lots of space - the machine seems quieter. They've improved the double-sided printing ability (my sample was on 24# uncoated bond) However, the white gel is the game changer - hassle free. I'm told that guys with flatbeds always must shake the white bags because of settling - you don't have that problem with Gel! even the single pass white samples I saw were opaquer than most! Coming from a 1640 (and we love the 1640) i thought the 1650 was awesome, well this blows that out of the water! (I really wish Canon would make use of that faux second drawer, and allow this to be a 4 roll machine)