Thanks, but I was asking the OP what particular reasons he has to move from IPB to XF

I am well aware of the things XF does better than IPB. However the biggest bummer for me XF has at this point in time is the limited feature set and limited advanced add-ons (there are way more add-ons for IPB than XF, paid or free). Pricewise you would pay more for a complete XF than IPB (User Essentials costs $30, Conversation Essentials cost $40, +20% VAT on all official XF add-ons for european customers etc etc.)