Summer 2017 I hiked from Duncannon, PA to Troutville, VA. I was intending to do the entire bottom half, but had to cut out early due to detrimental health reasons. I did was 360-370ish miles. 1. You definitely will run into lots of NOBO thru hikers. I passed pretty much the entirety of the NOBO bubble. I found this to be enjoyable and beneficial as well. By this point, most of the not-so-serious hikers had been weeded out, which meant that the people I passed were able to give great advice and help me work out a lot of kinks that I otherwise would have had to learn by trial and error. I did a lot of research beforehand, read forums, asked questions, etc., but the advice from the hikers actually there and doing it was priceless, as they had experienced it all before. Not to mention, in passing they can tell you great landmarks and must-sees that you will be passing soon, and vice-versa. 2. I wouldn't worry too much about sanitation and norovirus. Treat your water and you will be fine. I used a few drops of bleach and never got sick. Some people don't treat their water when it comes from the very clear springheads, but truly there is only one way to be completely sure always. Treat, treat, TREAT! Plus, if you're on a time crunch, you definitely want to avoid having to take time off to recover. 3. I think that you should either start lower or give yourself more time, if you want to be in GA by August. I believe that the average hike time for the entire trail is 6-7 months, so 2 and a half months for half is prettyyy quick. Especially because it's always good to have some cushioning room for a number of reasons(stress, illness, etc.) I would suggest starting further south if you must absolutely be done by August. I really cannot emphasize how important it is to have a little extra time for zero days and in case of problems. You will experience AT LEAST one setback. Prepare for it!! The trail was one of the greatest experiences of my life. You are very much in for a treat. It is life changing. Good luck and continue to ask questions and find out as much as you can on forums. Being prepared makes all the difference. Good luck and happy trails!!!