Since you have had a good experience with the Unicorn in the past, sticking with the Honda bike and going for the CB350 is a good bet. The CB350 is a comfortable, reliable and decently fuel-efficient machine which should last a long time without major problems, by and large.
The Royal Enfield Meteor 350 has a similar feel to the CB350 but has a more laid-back rider’s triangle. It won’t be ideal over bad patches of road. Instead, we recommend you look at its siblings, like the Hunter / Bullet / Classic, because with their more upright, neutral ergonomics, they will be more comfortable.
A test ride should help you decide between these 350s.