Thanks bama_ed! I knew I could count on you to give me some good advice! I am definitely doing the online checkin then, done deal!

I hate that we will miss you! I've already requested a specific loop (300-we are bringing the pups along) and we always tend to get that loop when I put in a request, but do my chances of getting a specific site increase the earlier in the day that we get to the Fort? Usually it's afternoon when we get there, but I'm debating on waking everyone up at the crack of dawn in order to get there early and get the magic started!

Lori, your chances of getting a request DO improve the earlier you arrive in the day. Here's how.
As I said earlier, all reservations are pre-assigned a site so that when you arrive, that part is taken care of already. However, getting a request is a function of how many vacant sites are available that morning. So let's say Lori and Ed both requested a pet loop in 300. However, due to random chance and available space, Ed was booked into 300 on a preliminary basis and Lori's request WAS NOT MET and she was booked into 500 loop across the street (just making this up).
If Lori can physically get to the Fort before Ed does and when she checks in, she will find that her site is in 500 and she uses her most polite voice to ask the Cast Member if there isn't any site available in 300. The CM will probably BUMP Ed off his pre-assigned 300 site and put HIM in the 500 loop and Lori will get into 300. If the site was vacant last night you can go right to it immediately. In the case where that site currently has a camper who is checking out that morning, you will get all your paperwork but be asked to wait to go to your site (they won't give you a site number so you won't know where to go but they will say you will get 300) so that it can be cleaned and prepped once the camper on it checks out and they will text you when it is ready (with the site number). Ed will never know he wasn't assigned 500 in the first place.
This happened to me on my 2012 trip when I arrived early (1130am, had asked for loop 1500, didn't get it on the pre-assignment, but asked to be moved to it and had to wait till after lunch before it was ready). The time before that in 2011 I had asked for 1500, got there early before the official 1pm checkin time, was given a 2000 site, asked for a 1500 site at the window, and was told it was full. So I accepted my 2000 site but pouted all the way as I drove to it. But before I went to 2000 I first drove around the 1500 circle and sure enough, honestly, every single last site had a camper on it. So I believe the CM will try to meet your request if they can by bumping a guest arriving on the same day who has not yet arrived. As I said, the late-arriving-guests are none the wiser.
The same approach works for specific sites.
So like before, it can't hurt to wake up everyone early on arrival day and get to the Fort early. To me it's worth waiting to get the loop I want. You can park in the overflow lot and visit the Trading Posts. We went to Downtown Disney to eat lunch and our text came during our meal. Be patient, be persistent, treat your CM with respect, and I believe they will try their best for you.
That's Ed's opinion, anyway. It's worth what you paid for it (zero). But I hope it works out for you.
Bama ED
PS - you may have been pre-assigned to 300 but in the case you weren't, getting there early gives you a chance. Nothing ventured, nothing gained. At worst everyone gets more Fort time on that first day.
PPS - sorry I am so wordy. I need to try to not be so verbose.....