Hi,
I just went live with OPC for VM2 with J2.5.x. It works fine. But I had so much headaches to customise the layout. Actually I created a new theme, to match the existing RT gantry template of my client. And I was very annoyed to find old VM classes and references all over the existing themes.
I supposed it is a hard to convert, but for the sake of design, and the future of VM2, it worth it, I'm sure.
I cannot spend hours converting the theme (I have my own extensions to develop actually), but I will love to help with testing and debugging. Let me / us know where do you stand as regards of template overrides.
Kind regards,
Hervé