Training. I was able to attend a national training in Tampa which allowed me to train with full-timers who had previously participated in internships. This experience was invaluable. When I finally met with other interns in my market, I had a strong sense of how internships worked at PwC. Also, I had made friends in markets all over the country. This has proved to be very beneficial in the start to my career.
Working from 8am-10pm is rough, but honestly it is certainly doable. Also, many accountants know that public accounting has rough hours. This was expected and tolerable. I disliked having to drive over 2+ hours to my client who happened to be in the middle of nowhere. Fortunately, I was able to stay in a hotel. Sadly, many of my co-workers had to drive 1-2hours each day and were not able to stay in hotels during the week. If I were to be given clients all near my house, my quality of life would be much better. I strongly disagree with the sentiment that a client 2hours away is still considered in your home market. If I am driving 2hours one way, put me in a hotel. And please don't put me in a hotel too often because I like my house. I have a nice house and nice things because I want to spend time at home, not in a hotel.
Advice to Potential Interns
Understand exactly what you are getting into. Understand that during busy season you will work hard, but you are paid well. There are lots of opportunity to advance in the Big 4 and you will have many more opportunities than if you went to a smaller firm. Just understand things are not always taught to you exactly. Lots of your job is finding solutions on your own. Seniors don't always have time to coach you (especially not during busy season). Don't get upset if you have to take some dinner orders or pickup coffee. It is all a learning curve.