Asking this question in a Ducati forum... I know what most will say.
Ok, my thoughts. The evo is less comfortable but more sporty and exciting (specially engine) than the CB1300. If you really drive a lot, keep the CB. If you drive your bike in your free time, vacations, weekends and other "special" occasions, go for the evo. Maintenance cost shouldn't be that much of a difference. Both fairly low maintenance.
Hope you get my point.
(ps, the engine is very addictive, specially with 14t sprocket and an aftermarket muffler. Have to admit that the stock is not bad at all too).