Results software is the most interesting of all investments that you will make.
The relationship you develop with the software vendors is the key. So how they respond to you when you are investigating and they are selling will give a preview as to how this will go.
Remember that no one plays golf with one club. Sure you can cover a course with a pitching wedge. It won't be pretty and no one will pay to watch, but it can be done.
We used several different packages for the results usually based on the sport.
You mention racelresults as a data collection option. Their software and data base management options are quite comprehensive. Contractors we know appear to be happy with the service level they receive.
Vola software and it's predecessors appear to have been offered to the public as a result of products developed for their own contracting business. So you may have to think like they do to fully appreciate and operate the software.
Thinking like the software designer is something to actually think about. This is not a large profitable business. Usually software is developed by interested individuals or partnership and grows from there. So you are really joining the partnership.
You also have the option to progress yourself if a particular package doesn't work out. So plan on switching if it doesn't work out. Learn from the experience and move on.
Most software companies or individuals offer demo options so you can hook up timers, displays etc. That gives you a partial picture. I would really spend the money and go to an event where the results are being produced by the software you are thinking of partnering with and see it actually work on site. Better to spend a thousand first rather than a drawn out entanglement. Easy to get on a plane to Europe or wherever and gauge the effectiveness on your own.