I started my researching at Somerset House. I think that was before St Catherine's House. It was, however, only the births, marriages and deaths records. We didn't have computers in those days! I must admit that having had that experience - which was truly hard work - it does make me very careful and methodical when I use the internet for all the other amazing records that we can now access.
My original interest was sparked by a handwritten copy made in 1955 of a document which started in 1625 and ran until 1825. I was assured by my late father (we are talking early1970's here) that it was connected to my grandmother's family. It took me years to find the missing link, by patiently getting the binders down off the shelf and making a note of the record, before applying for a certificate.
....BUT only recently, certain Parish records have become available on-line, and I have been able to see scanned copies of documents dated from the 1700's. It is so amazing to see the record of the births, marriages and deaths of these people. Also now available on-line are wills, censuses and apprentice records and a host of other documents. It makes everything so much easier. (But I do think people are careless these days, and just add things to their trees because they seem to fit.)
Sorry, that this is such a long posting - and I am not sure whether I have answered the original question or not!