LOL, Prince! I admit I haven't read Fraser's book - an oversight on my part, perhaps, but then, there are so many "Six Wives" books out there right now, perhaps I can be forgiven????
It's true that Starkey is not overly sympathetic to Catherine of Aragon, an approach which I rather liked, as a matter of fact. It makes a nice change from the usual fawning treatment of the Spanish princess. Starkey points out that early on in the divorce proceedings even Rome suggested that Catherine enter a convent in order to resolve the sticky situation, but she categorically refused. (BTW, Mary's position as princess would not have been in the least affected by such a change in Catherine's status.)
I guess what it comes down to is that if you want a well-paced narrative, read Weir. If you want technical detail, read Starkey. The former is more accessible to most readers, the latter more scholarly (but it still suffers from a certain lack of organization, IMO, and a very abrupt ending - I think he could have used a better editor).