The database upgrade is probably not noticeable to the human eye. Individual database operations improved about 10-20%, however we are talking improvements from 75 milliseconds to 68 milliseconds, and 185 milliseconds to 152 milliseconds, and from 12.5 milliseconds to 11.5 milliseconds (there are 1,000 milliseconds in a seconds). But little changes like this can add up.
The query optimization was more important to the Participant Report, probably saving a half second to second. The first query of your participants (even with races with 20,000+ participants) should now be under 2 seconds and subsequent queries will be sub-second with fast internet and a decent browser and computer.