How many contacts and/or how large would the DB containing the same have to be before the same begins to take more than two (2) seconds to enter new and/or save modified contact data?

When I had 785 contacts it took approx 30 seconds to access the note field in a contact and/or save data in the same. After deleting 100 contacts and reducing the size of the DB to 9.7MB it now takes approx 15 seconds to save data in the note field or save and exit the contact.

Has anyone else experienced this? Anyone have address DB's larger than 10MB? If so can you confirm/deny my theory that contact/address DB's 10MB or larger delay the application's response time? A friend with the same phone sees no delay in the application while processing his 40 contacts.

Thanks in advance!