It depends a bit on your situation.
I would definitely recommend the PPH over ESS if you want to give your teens the freedom to go to and from the parks or DTD a bit on their own. I took my DS, age 15 at the time, with his 16 year old friend. We stayed at the DLH, and they really enjoyed a little freedom. The next visit, my DS and I stayed at the ES, and I got too sick to go to the parks one day. My DS didn't feel comfortable enough to take the ART to the parks on his own, so he just hung out at the hotel all day. He would have gone to DL had we stayed on site. My DS definitely prefers staying on site over the ES.
Another advantage of staying at the PPH is that you can take advantage of EE each day that it is offered, and you won't have to worry about ART or parking. That will save some time. I think the pool area is nicer at PPH.
Now ESS is a very nice hotel, and the suites offer you a lot more room with the outer sitting area. Be warned though, if you get stuck with a room near the elevators, this area can be a bit noisy to sleep in. The breakfast is pretty nice, although we seldom took too much advantage of it since we were always in a big hurry to get to DL before opening to take advantage of the smaller crowds first thing in the morning. There are lots of other hotels around, and a Target very close. I'd feel pretty comfortable walking around the area during the day, but wouldn't stray too far from the hotel late at night.
When we stayed at the ESS, we ended up driving for various reasons, but I agree that ART is probably a better way to go most of the time. If you do decide to drive, you can still do EE; the parking structure opens 30 minutes before EE opening on EE days. I strongly recommend being at the parking structure when it opens so that you can get to the gates well before opening whether its for EE or normal opening time.