Have you found a reliable method for evaluating the ROI on any GenAI investments you've made? Is it any different from other technology investments?

Depends on the GenAI use case.  In some instances, ROI is the same as other tech investments.  It is time savings.  When GenAI is creating a new capability, the value gets more difficult to measure.  

As with any new technology measuring an ROI can be difficult, if not impossible. These investments can be incredibly innovative and game changing.

My recommendation would be to have clear guidelines and budget on how much you want to invest in these technologies (time and money) and how you will measure the success of the investment as aligned with your strategy.

If GenAI investments support your strategy, it should contribute to building your long term ROI.