With GPO - and KP1 - exporting the score added for legato slurs pedal marks (CC#64) and overlapping notes (as stated in GPO concerning real legato playing). Also staccato and staccatissimo had their counterparts in the exported MIDI file.
Using KP2 as VST instruments, Overture ignores those legato slurs, NOT adding pedal marks (CC#64), NOT lengthening the notes to overlap, and the staccatissimo doesn't have its counterpart in MIDI.
Why? This gives me extra editing work in Sonar, I hadn't before using KP1.
Raymond - also posted at the Overture forum
This is true. I have two the two versions side by side installed. With Overture I still use KP1, because it has the definition file for GPO set so that it will automatically insert all the things you need, like legato and keyswitches. I don't think there was ever a definition file made for KP2 and GPO and Overture. Although recently someone mentioned the file that is available on the Overture forums. I think it was written by Tatsu Nagao. I have downloaded the file and "installed" it and it seems to be functioning, but I haven't actually tried it in detail.
I think the legato feature is particularly affected because it now uses another controller instead of C64. I think this is so that one can use the GPO Steinway with normal sustain functions and the legato feature at the same time. This is of course not possible with KP1.