original choc mini (early 2011 I think): different mappings in the nav column, bad keycap lettering infill, thick case, modifiers of different sizes, fixed cable, no backlighting
2011: changed nav column mappings, improved infill
2012: thinner case, optional backlighting with black ABS keycaps (could have existed in 2011)
2013: uniform-size modifiers, detacheable cable, wireless-ready case
2014: optional wireless, optional backlighting with black POM keycaps
future: Gaote switches instead of Cherry MX
I could have missed something. Also, choc mini wasn't available fairly often even for several months. There was a white PBT version as well, probably discontinued after the 2013 generation.