We recently bought SX.enterprise, and it's been good and bad. I'm posting a critique- especially of SX's UI- at
http://asimplenumber.blogspot.com . Comments there are welcome.
No doubt the user interface is not perfect. I do have a solution to your issue concerning prepaying vendor invoices before receipt.
You can pre-pay vendor invoices using the APEI (Invoice Processing Centre). It allows you to pay invoices before the product is received. You cannot pre-pay an invoice using the standard APET function. APEI was added in version 3.2 of SXE.
From the APEI docs:
AP Entry Invoice Center AP Entry Transactions
You can match the invoice to the purchase
order as soon as the invoice is received,
even if the purchase order has not yet
been received in PO Entry Receipt of
Inventory. The Update portion of AP Entry
Invoice Center Final Update or AP Entry
Group Update posts the payable to the
General Ledger Payables account as soon
as the invoice is entered and updated. This
causes General Ledger Payables to be
accurately stated. Later, when the
purchase order is received in PO Entry
Receipt of Inventory, the purchase order
costing reconciliation occurs to update the
appropriate Inventory Control accounts.
John Jackson