SQL Server big tables or store data in a xml field

I have a .net solution with a big form with many data that the customer need to fill, like a form with many steps to fill all data we need to get.

So i was wondering if it's better (from a performance and design approach) a traditional big table with many fields, o store the data only on one field of XML type.

Example of one "TraditionalTable":

RecordId	CustomerId	Data 1	Data 2....	to Data N
1	120	01/01/1980	abcd ....	123
2	20	04/02/2004	fgh ....	230
3	10	05/01/1995	xyz ....	135

Example of one "DataWithXMLField":

RecordId	CustomerId	FormData
1	120	< data>< customerdetails>< borndate>01/01/1980< /borndate>< /customerdetails >< financialinfo >...."