From what I have seen the pros are that sometimes it works out absolutely great for the kid, and the cons are that sometimes it's a disaster.
To amplify on this a bit. My son played with 2 kids who committed to the same major conference school during their sophomore year of HS. It was a dream school for both. One was a 2016, the other a 2017. Subsequently the recruiting coach moved on. 2016 was given an NLI and played extremely for the team this year as a frosh. 2017 was left dangling and never saw an NLI. Fortunately he found a nice mid-level conference match a month or so ago and signed.
Sometimes it works out great. Sometimes it doesn't.
You could make the case that despite its flaws the system worked well and each kid wound up where he really belongs. But I can't help thinking the 2017 got lucky in the end and would have had a much smoother ride without the early commit.