I've read that the optimal size for a city is around 700,000 - big enough to provide services but not so big as to be unwieldy. With a population of about 140,000, Oxford is a fair bit short of that, but as one of the UK's two premier university towns it ranks way above its size as a cultural and intellectual centre. (For comparison, similar-sized cities are Cairns in Australia or Lancaster and Newport in the UK.)
I've posted before about Oxford's bookshops, but it also has an impressive array of other resources. The Ashmolean, the Museum of Natural History, and the Pitt Rivers are the big museums, but there's also the Bate Collection of Musical Instruments, the Christchurch Picture Gallery, the Museum of the History of Science, the Museum of Oxford, the Museum of Modern Art, and the Bodleian Library.
There's a busy theatre and music schedule, especially for anyone keen on choral music. So far I've seen performances of Anouilh's Antigone (the Oxford Theatre Guild, at the Playhouse), the Monteverdi Vespers (the Arcadian Singers and the Monteverdi Ensemble, in the Sheldonian), and classical Middle Eastern music (Oxford Maqam, at St John's). And I've performed in a Javanese gamelan concert as a member of the Oxford Gamelan Society.
And for facilities and resources not available in Oxford - a full symphony orchestra, for example, or a serious opera hall - London is only an hour away by train.
Is the Ashmolean open yet? It was closed for refurbishment when I was there last year. :-(
The History of Science Museum is awesome though.
Yes, the Ashmolean has reopened. I've only looked at two galleries out of nearly seventy so far - the refurbishment added forty. (I've been visiting the Ashmolean every time I visit my dentist, which is making it expensive even though the museum is free!)
Do you remember where you got that figure for the optimum population of a city is?
I couldn't find the precise reference, but there seems to be quite a bit on this, largely in the human geography and urban planning literature.
I'm thinking purely of my personal preferences here. There's no reason for the optimal size for an individual to match the optimal size for society, where one has to take into account social and environmental costs as well as individual well-being.
The housing in Oxford, at least the bits I've seen, is almost exclusively medium-density. Mostly terraces, with some larger houses mostly built as semis (and in some cases converted to flats). There's nothing over three stories and (at least around here) almost nothing over 250sqm. But it's not as compact as it might because of the large areas of meadow that flood when the rivers rise.