Stanczyk has used and forgotten the following website many times over; It has been online for a LONG time. This website appears to an historical collection of data by a single individual. Here is my best guess as to the Inventory of Materials at the website (all in Polish):
Historical and Genealogical Materials on the history of the nobility of the Wielkopolska from the 15th-20th Centuries. Complete inventories of municipal and land books of the State Archive in Poznan and the books of vital records inventories framework of the same archive as well as the Archdiocesan Archive in Poznan and the Archdiocesan Archive in Gniezno. These were apparently collected by a man named: Włodzimierz Dworzaczek [US Libraries/Archives might call this, his collected papers].
Website: Teki Dworzaczka – Biblioteka Kórnicka PAN [a Polish Science Academy]
Ease of Use: Slightly Difficult for English Speaking and/or non-residents of Poland
So if you have ancestors who were from and/or passed through the Western part of Poland, including Poznan and Gniezno, this site has indexed church mertykal records and a great deal of court records too. So far it has not been of use to me, as my known ancestors are predominantly from south-central Poland. But if you have some royal blood (for example Leszczynski), there are many records that can provide you abbreviated notes.