Went to check out the XA50 and XA55 the other day. After 30 mins of testing, I end up getting the XF400 purely for the 4K 60p (although in Singapore we only get 50p) and the larger LED screen.
The Z90 is nicely priced between the XF400 and XF405. When XA50 and XA55 come into the market, things might change a bit.
Perhaps the XA55 is positioned to compete with the Z90.
The review on the new XA50 and XA40 are limited at this point. But based on specs alone I think XF400 will still make a better video camera despite its been in the market for almost 2 years. Do you have any experience shooting with XF400?