Any thoughts on this?

You can limit the number of sales orders by adding filters.  Here's an example where I set up a date range filter for Receipts:

         Receipts = Company.Factories.ReceiptFactory.List();

// Note, I have a using statement for "using API_COLLECTIONS = Sage.Peachtree.API.Collections.Generic";
API_COLLECTIONS.FilterExpression filterExpression = 
API_COLLECTIONS.FilterExpression.GreaterThanOrEqual( API_COLLECTIONS.FilterExpression.Property("Receipt.Date"),
                                                                                                 API_COLLECTIONS.FilterExpression.Constant(new DateTime(2015, 3, 1)) );

API_COLLECTIONS.FilterExpression filterExpression2 =
API_COLLECTIONS.FilterExpression.LessThan( API_COLLECTIONS.FilterExpression.Property("Receipt.Date"),
                                                                               API_COLLECTIONS.FilterExpression.Constant(new DateTime(2015, 4, 1)) );

API_COLLECTIONS.LoadModifiers modifier = API_COLLECTIONS.LoadModifiers.Create();
modifier.Filters = API_COLLECTIONS.FilterExpression.AndAlso(filterExpression, filterExpression2);
modifier.Filters = filterExpression;

Receipts.Load(modifier);

Hope it helps!

Thanks so much. That makes my application run SO much faster.