I did find remarkable correlation with the suggested hints, same name, DOB, address, names of children etc. I guess because I have a reasonably unusual surname it may be a bit easier but of course there could be cousins with the same name born close together which will be traps for the unwary and inexperienced people like me.
A few more comment about your "back to the 1700s":
"
because I have a reasonably unusual surname it may be a bit easier" - true but for your father's "side" of the family you're talking about probably something like 5-6 generations back from him, 32 or 64 ancestors of which only one has the same unusual surname. So not much help overall.
When I started going back looking to build one quarter of my tree, I traced that particular branch back to the 1700s quite quickly, mostly because in the diocese of Durham, and to some extent for the Kent line too, the parishes often recorded details such as both parents' full names for baptisms, father's name of bride and groom for weddings and maybe age at death for burials. And sometimes the place of abode as well. Then you switch to another line living in another part of England, and you get "James son of William Harris and his wife was baptized this day" or "Margt Richardson buried on ye 27th day of ..." (baby? mother? gran? no age given)
So if you have been lucky with one branch don't assume you will be for the next one.
And I would agree, keep your tree (in other words keep the information you have amassed) on your own computer and/or on paper at home, don't rely on a commercial online site.