Properly serviced, neither movement is better than the other. But a gen movement will do 2 things an ETA cannot do - 1. It will increase the watch's resale value & 2. It will give the wearer (your wife) the confidence to walk into any AD with impunity, which, to most women, would be worth the additional price alone. Also, at some point, like most of us, you will regret damaging a gen dial (to fit the ETA) instead of going all-gen, which will ultimately cost you more when you end up buying the wife a gen.