Wendy,
Yes, it is the smallest County Record Office I have visited, and sometimes it does get pretty full - especially after a bank holiday, or indeed on a Tuesday (it's closed Mondays and at weekends). There's a plan to move to the outskirts of Cambridge to larger premises, perhaps in 2-3 years time.
So, yes, I'd advise booking in advance, and maybe a microfilm reader or microfiche reader, as there are very few of them...
Keith
n.b. At Cambridge, if records have not been transcribed in volumes of books (and they've done a particularly thorough, extensive job of this here), they tend to be on microfilm (parish records and wills); not much is on fiche, just items such as Probate Records.
Bury St Edmunds, by contrast, has a much higher proportion of their Suffolk parish records on fiche, which I found made searching slightly easier than wading through miles of microfilm...
