I'll keep my thoughts on the idea of "punishing" a town to myself!
I am not near as well traveled as many here but learned a few years back that altho RS books are terrific in most respects, they are his opinion, his likes and dislikes. (We found a few of his must dos in Paris to be underwhelming and unimpressive).
For this trip I used his Italy books then did a whole lot of my own research. He brushes off Pienza and for some reason that town appealed to me. I think it was Roberto who sang Pienza's praises here on forums so we included Pienza in our itinerary. We absolutely loved the town, had a very delightful visit- it was charming, friendly and beautiful. We decided that is where we will move to - if/when we ever move to Italy!
I was also so sure I would love Siena- we gave it 2 nights. One would have been enough. We just didn't get any warm and fuzzies there. The Duomo was fabulous, probably most impressive church we saw in Italy- so for that it was worth it. But I do wish we had given that 2nd night to somewhere else.
You have to do your research and make your own decisions as far as itinerary- what to see, what to skip.
As far as Vicenza- have not been but we have new neighbors who just moved here from Vicenza, they had lived there for 5 years, bought a home, etc. Loved it and shared their photos, experiences there- if we could have altered our itinerary we would have stopped there just on their advice. And I did wonder why it was not even mentioned in RS books!