Well, you can sign me in the list of those who would like the banking up-down feature on the FBV Express!
As a customer, I think that 100 euros are not worth the bank-switching feature...I'd more likely save 4 presets I really like in the default banks of the amp and use the Express board to switch between them!
the Shortboard adds extra functionality like effects control which the Express doesn't...a customer that goes for the Express probably doesn't need much more than switching channels and won't buy the Shortboard anyway.
I also don't believe very much that it would be hard/impossible to implement the feature from a technical standpoint, as efxtr suggests...
In that sense, it would be nice, at least, to hear from Line6 why they can't do that...
I am going to buy the Express anyway pretty soon and I'd like to switch banks with it, if it was possible...
