One of those things you just have to do, and it holds up. The fountain itself is genuinely…read morespectacular up close, bigger and more detailed than pictures do it justice, and seeing it in person is worth the chaos that surrounds it. And there is chaos: the piazza is packed at pretty much any hour of the day, so go in prepared for a crowd rather than hoping to find a quiet moment.
You can pay a small fee to get down to the basin level for a closer look, and the line to do so can be long during peak hours. We found that arriving just before dinnertime cut the wait considerably; most of the daytime crowds had thinned out and we were through quickly. If your schedule has any flexibility, that window is worth targeting. The view from the piazza above is free and still solid, and getting down to the edge is not required, but a neat bonus.