NOBILLGATES  after having lots of troubles with ibiz 3 (scrambled or lost addressbook entries, ghost-invoice or orphaned invoices with no relation to customer, unusable interface, and more of these weird bugs), I switched to grandtotal last autumn and would never never never turn back.  
(Version 4.0)

NOBILLGATES  after trying v 3.1.5 for a few days i turned back to version 2.5.

ibiz 3.x is incredible slow (on an macbook with 2 gb ram an 2x2 ghz!) , takes over 100% cpu and several minutes to changes from project to invoice-view, meanwhile it blocks everything else. it has still no import or export function (i.ex for excel or filemaker), ittrashes addresses, has a bad gui, and so on. this programm is not worth a dime. very disappointed.  
(Version 3.1.5)