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Notes in italics from Oxfordshire by Jennifer Sherwood and Nikolaus Pevsner (1974)
Yale University Press, New Haven and London.

The building as we see it was begun in the C12 but towards its end ... At the time of the Reformation ... some bays of the nave were cut off, perhaps about 50ft, to make Tom Quad possible. The result is small for a cathedral ...

Crossing tower, Norman and entirely plain with a few arched windows in the lower stages, and E.E. (Early English), and probably mid-C13, in the upper stages. ... The S aisle has Perp windows (not visible) and battlements, the clerestory E.E. windows, shafted. All this is drastically restored. The W side of the S transept has better preserved plain Norman windows below (not visible), shafted Norman windows above. ...

The E wall is all of the time of Scott's restoration, i.e. of 1870-6. It was a thorough restoration ... Scott removed a large E window of 1853 and installed a Norman rose window, on the strength of traces far from conclusive. The details anyway are all his. Original are the square angle turrets, at least in their shape, and the shafting above the rose window. ...

In the choir the system is at once established which was not to be changed to the end of the building operations. It is highly unusual, though not a unique system. Tall round piers carry arches, and there is a triforium, but this is not above the arches ... but below them, tucked into them. The aisles are therefore not as high as the piers, and so second arches are needed below the triforium. ... The super-arches have strong roll-mouldings. But the sub-arches are unmoulded, and there is no visual or structural logic in the way they touch the piers. ... The nave modified but did not alter the system. There are now alternating round and octagonal piers ...
The capitals throughout are of great variety, and few are run-of-the-mill. .. As we have no dates, and as crockets appear everywhere and waterleaf rarely, and as moreover  broadly speaking waterleaf was popular to about 1190 and crockets after 1190, the usually accepted dating to the last quarter  of the C12 for the whole building seems too early, and something like 1190 to 1210 is more probable.

As the highly ingenious system of vaulting is very close to that of the Divinity School, and as the Divinity School was vaulted in 1480-3 by William Orchard, one can perhaps assume a date about 1500 for the priory choir and look to Orchard as its designer, especially as he was buried  in the cathedral. The vaulting bays had to be oblong. The designer wanted to make them square. So he started from N and S by big and strong arches treated exactly as if a timber hammerbeam roof was intended. Even the pendants are as in such roofs. The areas between the hammerbeams towards the windows are panelled. The windows have a wall-passage and their heads are panelled too. That left the designer his sequence of square bays in the middle, and they have complicated lierne star-vaults  with many bosses. The thick arches seem to disappear behind that vault. 

Transepts. The system is the same as in the choir, only the Perp vaulting does not extend. ... Both transepts have ceilings of c.1500. ... The N transept has a large Perp N window of five lights. ... The S wall of the S transept has a Victorian vestry in C13 Gothic. This belongs to Scott's work. Above .. window of c.1300. The crossing tower arches to the transepts are pointed, whereas those to the nave and choir are rounded - see south transept picture above and nave picture near top.

The Lady Chapel was added N of the N choir aisle. The wall was replaced by piers with clusters of shafts, partly with fillets. All have small and pretty crocket capitals and finely moulded arches also with fillets.
Memorial: Robert Burton, died 1639. Bust in oval recess. Emblems l. and r. Burton appears duly with an inscription referring to Melancholy.