Andrea - we really like Verona, an interesting and pleasant city with some beautiful buidings. It was the first place we saw people riding bicyles rather than those d****d motor scooters.
We are lucky in that we can pop over to Italy easily so are not forced into either/or decisions. If that were not the case and I had to choose it would be to spend more time in Venice because it is unique and a daytrip would not even really scratch the surface of what makes the city so special. It is not only seeing "the sights" but also wandering around the streets and different neighborhoods or sitting in a campo or by the water eating an icecream and feeling the history of the place. However, if you or time constraints decide that a day is all you have, then go for it. Do as we did and put down markers for a future longer visit
Only you know what interests you and your husband, not everyone falls in love with Venice and often a short visit is enough for them.