Bristol is a fantastic city. Maybe a kind of British San Francisco in terms of its hills, diversity and hipster/arts scene? Much bigger and more urban than Bath, with a lot of students and so much history.
Bristol was the focal point for some of the protests in the wake of George Floyd, with the statue of John Colston (who made his money from slavery) being toppled by protestors, and that felt a very quintessentially Bristol thing.
The SS Great Britain is perhaps my favourite of all the many historic ship museums in the UK. Clifton offers classy Bath-like Georgian houses. Brunel’s Clifton Suspension Bridge is unmissable. There is a wonderful Tudor merchant’s house (the details of which I forget). Numerous Banksie artworks. Great food and drink. What’s not to love?
I’d say that perhaps it’s a bit more challenging and much less “quaint” than Bath, but (like Liverpool and Glasgow, with which it shares maritime DNA) it’s truly one of Britain’s great cities.
Oh, and in terms of Stonehenge, it’s an easy train ride to Salisbury, from where you can get the Stonehenge tour bus. And Bristol is also a very easy short train ride to Bath.