I just got my Mobile Zeo about a week ago. So far, I like it.  I do not use an iPhone, but I use an Android and I have an app that works for it.  Basically my sleep data syncs with my Android phone (Droid RAZR MAXX) via Bluetooth.  The charger unit has 1 port. There are two different cables.  One for the AC charger and one for your computer (USB).  You would have to switch plugs.  That is a little annoying but it's not a big problem.

I have so far not had any problems with "crashing" or "losing data", but it could be too early to tell.  I also feel that it is accurately measuring my sleep.  I'm actually currently on Restoril, which is a sleeping pill.  So once I'm asleep, I'm asleep until I'm done sleeping.  I don't wake up.  Once my average "ZQ" score improves, I'll try to stop taking sleeping pills and see if I still need them.  Seeing this "comfort" on the screen, knowing that I'm sleeping well might be enough for me not to have to rely on pills.  Right now, my average is 57, but I've had nights where my ZQ has reached 87. I still don't quite know what ZQ is, but I imagine it has to do with your age in relation to the amount of sleep you're getting each night and the Zeo averages it out every week.  I have a horrible sleeping schedule for a number of reasons, but I'm going to try to fix that this week.

I just checked Amazon and there's a newer version available called the "Pro". Not sure what the difference is, and there are no reviews on it.  For now, I'm happy with what I've got...until it breaks.  Hopefully that doesn't happen.