Inverter II improves a lot on the original, most importantly it does not have a foolish curved back (no ones hand will be comfortable with that) which caused whatch to always sit awkwardly slipping either way... The watch looks much better, the size is perfect and i do not know if this is deliberate or not but as you make a gesture to look at the time its just right to get the weight spin. However it arrived with serious lag, within 24 hours it lagges 2 hours but i have not seen such thing with any of their other watches (i have 4 others). The customer support is super friendly and they will repair it for me with no charge. I think this is likely a one off rough shipping incident. Love the watch.