http://www.timesonline.co.uk/tol/comment/columnists/magnus_linklater/article...
"I did a quick test on my own, looking up Nancy Mitford (I'm a fan) and judging the results on time and accuracy. Wikipedia gave me four pages of almost 100 per cent accurate information (I rang her niece, Emma Tennant, who spotted one small error), together with 33 links to related characters and a 16-line bibliography suggesting further reading. I got the whole lot in ten seconds.
"The Britannica required a 20-minute trip to my nearest library. It gave me 350 words and a bibliography with one entry (Harold Acton's memoir). The online version offered the chance of signing up to a 30-day free trial, but still required my credit card details, replete with reassurances about taking my privacy "very seriously" - always a worrying sign. The DNB provided by far the best and fullest entry (but so it should). However, a month's subscription costs £29.35, and a year will set you back £195 plus VAT."