OK, I'm back from my tests. Since I'm a late convert to GPO, everything was already up to the latest version (perhaps with the exception of Studio, I couldn't tell HINT TO DESIGNERS: Add an ABOUT GPO menu item to read out the version # so I don't have to go hunting for file versions).
My major latency issue that I thought was an overture problem turned out to be a bonehead error on my part with Studio. I thought since I had the single GPO player working fine, that the settings carried over to Studio. In fact the thing was configured to use my cheesy mobo sound card rather than the RME card (I should have been paying more attention to the RME VU meter app that would have told me what was plyaing).
There's still some latency but it's not horrendous like before. One question remains: When I start up STUDIO it dumps me into to some ASIO test program which ALWAYS says it fails (even though things seem to work OK afterwards). The pop up error refers to a troubleshooting PDF file which doesn't seem to match any PDF file on my GPO CD's. I poked around on the GPO website, and didn't find much help (other than to disable GIGASTUDIO which I'd already done).
I'm still having problems with Overture. I downloaded a demo copy of Sibelius which seems to work much better for me. I have some questions but they probably will be answered by reading the manual (which doesn't come with the demo download).
Any ideas on the startup test failure?