I say do it , if your thinking about it's time for change & if you don't like the EVO sell it & move on, I say this assuming your looking at a used EVO (just don't over pay for it) if your buying new you better make damm sure it's what you want.
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).
If you've never ridden a twin cylinder Ducati before you will absolutely hate it at first, especially after a big smooth 4 cyl Japanese motor. Once you get used to the character of the motor it's addictive. Yes it vibrates, may miss a gear now and again, pops and farts when you change down, but I like that interaction it's what riding motorbikes is all about to me. Wind her up from 2k and surf on that wave of torque, then close the throttle and listen to her breath....
Oh and once you have one you won't believe how many 'extras' you'll need - more than you ever find in your Honda accessory catalogue.... and they don't change models every 2 yrs....
Do it, you know you want to, but are you brave enough!?!?