I think there's a lot of pros to ESD:
1. Coaches are able to "lock in" a percentage of their class, and then have time to look for "backup plans" if it doesn't go their way. It feels like recruiting is much less "scramble to get your guy" nowadays. I think that is a good thing in terms of giving coaches time to really evaluate who they want, and set boards. You may have a surprise in December, but you have a month and some change to try to evaluate and find other options. I like that.
2. It does allow for student-athletes to be able to shut down their recruitment and enjoy the holidays without having to worry about a million texts/phone calls/visits.
3. It allows for late bloomers who have developed well in their senior season to get their tapes evaluated after ESD, and have a better shot at landing in a good spot for NSD. If your season ended in December, and coaches weren't on you until this year, you may not have gotten a fair shot. I feel like what we see most is that those who sign on ESD have been pursued since early high school. The period between ESD accounts for a lot of "diamond in the rough" type players whose senior seasons propelled them further.
4. Having more of the class filled out, coaches are able to focus on bowl prep, and on evaluating and recruiting future classes. I feel like this can only be a good thing.
However, there are also cons:
1. For schools that are making coaching changes, ESD really puts them at a disadvantage. Ole Miss/Mizzou/Arkansas for example, have 13 days to put a coach in place, and even then, there are position coaches and coordinators that have to be filled. This makes the relationship building difficult, and will likely set those schools back a year.
2. It does put pressure on the student athletes to make decisions sooner, for fear of missing the boat. This could cause a lot more rushed decisions, and eventually more transfers down the road.
3. For teams whose trajectories are skepticized (such as Tennessee at the moment), ESD happens before a bowl performance. What happens if Tennessee draws Michigan or Penn State, and suddenly blows them out? Would that make a recruiting difference? It might, but it only would matter for those not signed. (Of course, the inverse of this is true as well)
4. I feel like it makes National Signing Day less special, personally. I used to treat National Signing Day as a holiday, but now, it's the Early Signing Day that has been the "holiday." You can look at it as two Christmases, but I do feel like it takes away some from the kids who wait.