Connecting Civicrm to Quickbooks classes / subclasses
We use Civi &amp; QuickBooks. Our QBs is only used for accounting. If we need to see donation details, we look in Civi. We do not record contribution detail in Quickbooks. We do not see a need to have that data stored in two places.

We just record the deposit in QBs. We use Class in QB for our Functional Expense allocations (Program, Restricted, and Unrestricted). Note, since most donations are not related to Functional Expense allocations (other than Program Income), we have created 2 additional Classes in QBs--Unrestricted and Restricted. So most deposits are recorded using these 2 QB Classes. We use Customer Job in QB for Line Item detail from Civi (General Fund, Building Fund, Scholarship). We do not have any donors entered as a Customer in QB.

We have our payment options in Civi to match our payment processor's deposit schedule. ACH, Visa/Mastercard, Discover. That way we can pull Line Item reports by Payment Type and date and they match our Processor Deposits. Then we record that deposit in QB with Class info (Program...) and Customer Job (We sum the Line Item Types from Civi and have one line on the Deposit entry for General Fund, Building Fund, etc). 

FYI, we use the same Class and Customer Job options when recording Expenses in QBs. This allows us to run reports by Class to see Functional Expense (for expenses we do have QB Classes for Management &amp; Fundraising). And reports by Customer Job to see Campaigns-showing income and expense for Capital Campaign.