I think you are probably OK with the 2.3.3 upgrade. I upgraded from 2.3.2+ recently to 2.3.3 and I don't remember there being any database upgrades. However, there is a fairly significant gradebook issue in 2.3.3 that is fixed in 2.3.3+, so you may wish to consider applying the next update as well. Of course, you could wait and see if you actually encounter the problem before you upgrade again.
We tend to be middle-of-the-road as far as upgrades, rarely upgrading to the latest version. However, there was a feature in 2.3 that we wanted so we made the jump. Unfortunately, we've hit bugs in 2.3.1, 2.3.2 and 2.3.3 already so it hasn't been the most positive experience. I'm hoping this latest gradebook issue is the end of the issues that hinder use. So from that perspective, I upgraded because the issue seemed like it would likely affect our teachers before too long. See https://moodle.org/mod/forum/discuss.php?d=215654 for more info.