I have a small subset of Customers, call them "SuperCustomers", for which sales people need to have a LOT of additional information presented to them.  These SuperCustomers represent a tiny fraction of the number of Customers we have in the database, perhaps <1%, but they are important to us.

I need to add dozens, perhaps even HUNDREDS, of additional fields (organized in subtabs) to satisfy what the sales team is asking for.  I'm wondering, will there be a performance hit for adding all these fields?  And will adding all these fields to the Customer record type cause problems and performance slowdown elsewhere?  I already have a SuperCustomer custom form, so the fields would only be displayed for SuperCustomers, but still...the fields are there behind the scenes.