I once used the address shown on a marriage certificate to carry out a 1841 Census search. The address was recorded on the certificate as: "Turkshead yard". It would not come up with a result on FMP 'search by address'. So out of curiosity I tried a search on Google Earth (with little hope that the address would still exist in Preston). Google Earth said "did you mean Turks Head Court, Preston ? ..
I am not greatly enamoured with 'address' searches on FMP. Great by concept but from my own experience a totally frustrating experience. Let me explain.
My ancestors to a very large extent are based in and around Birmingham, although many originate from Worcestershire the neighbouring county. When unable to find them by a person search -which thankfully is quite rare, thanks to the backup by Ancestry - I then try an address search; almost always in Birmingham and it is no surprise when right up front it refuses to acknowledge the street or road exists.
Like Emjay's example, nearly right is not good enough, or even very nearly right. Soundex names do not work (for instance Beech Street will not work for Beach Street) and is totally unforgiving with mis-spellings, even if you are copying something from a previous Census.
What really winds me up is when it finds the street but then only shows a portion of the house numbers. By trial and error you find the other part comes under (say) Aston. And if you second guess it must be Aston, the part you want is in Birmingham.
And I know, they know and everyone knows all come under the Metropolitan town, later city of Birmingham.
And then there are the legendary Birmingham back-to-back houses and how they are shown within the street - that varies from Census to Census and often within the same street . So 3 back of 10 can be 3/10 or 10/3 or 3 Court (along with 4,5 6) without reference to its prime street number which might appear on its own. This is repeated with every 'Court' so you have to search them all to find the one you want. If despite all this you fail to find the family, you still do not know if it is your searching or indicative of the family moving.
Of course none of this prevents a first time search of a small town or village being spot on. That happens of course, but just be wary of searching a large City with ancient boroughs. Get it wrong and you will search in vain! Give me person searching any day!