RugbyFirst - light my blue touchpaper and run ! The whole project (Trafalgar it was called !) has been poor - I was involved at the early stages as a Society 'end user' and gave them my views (as a Society Chairman and as a Times 100 plc company IT & Applications Director !). Apparently they knew best.
RFU Web Site - still crap, badly designed, and little updated outside of news page.
RFU RugbyFirst members database - duplicate entries, mysterious deletions, poor reporting, no data upload, and not reliable.
RFU RugbyFirst Appointments system - massive input from a number of Societies at spec, development and testing stages - still not live (all a bit of a joke really).
Five years in development, wrong technology used, poor implementation, and RugbyFirst still doesn't work.
Excel works just fine for small Societies ! For 150 appointments in a season, RugbyFirst (even if it worked) would be totally inappropriate as it is not desigfned to handle lots of last minute changes.
London Society and some others have a reliable software tool built and now running pretty well over a number of years, and a few Societies (and SRU) use a USA based software costing $200 licence.
If I were you sgoat stick to Excel !