5 months on and the Chromebooks are holding up really well.
2 have developed video faults and been replaced under warranty. 1 had something left on the keyboard it and the screen was closed, hard. 1 broken screen. But other than that we have plenty of working chromebooks. They are used for at least a few hours every day that school is open.
The hammering these things take and survive is a marvel. One of them had a milkshake dumped in it. It went right through and was oozing out the bottom. Yes, it took 3 hrs to strip it down and clean it out but 3 months later its still running. Not one battery is showing signs of not holding a charge. I hate to think how many have been dropped on the floor but they just keep running. Yay SSHDs!
As for our crappy internet connection. We are doing ok. We have limits. Khan academy can only be used by 10 or less students at a time. Youtube is listed as a no go areas for students. Our connection hits 3 instances of you tube and thats it. Things stop working. But, they can all use google apps without issues.
Now heres a bit of a plug http://www.ubnt.com/unifi we got 6 of these unifi A.Ps and it made a huge difference. They really can handle a lot of users at each point. Quite easily doing 30 users per access point and I would imagine they could handle even more. And, they are cheap. The initial setup is a little annoying but once you get the software going and 1 access point running its simple to add more.