Russell, the paper looks good, why not send a copy of it to the vendors of the two products and ask them to indicate what their tool can do and how it does it for each item. That's what we do and usually it is works.
I support what Rich states - however I would relook at some of the questions to avoid Yes/No answers unless that is what you are looking for.
Also from my own experience the Vendors will tend to interpret you questions to their product functionality so you will still need to get them to provide demonstrations and if you have time do an evaluation
Are you comparing like-with-like on these tools ? From your requirements link, it looks like much of the need is for load/stress testing, and I'm not sure that ROBOT covers that area ? Unless it's changed, ROBOT's target used to be functional test automation, similar to WinRunner and SilkTest ? Whilst you may be able to run multiple ROBOT scripts to generate loads, you may run into licence and hardware issues : the purpose-built load testing tools (LoadRunner, SilkPerformer etc)usually allow the simulation of multiple virtual users per box and should provide a more cost-effective licensing arrangement if you're looking at high user vols. I did see something on the Rational site called 'Performance Tester' but I'm not familiar with that tool.