Enterprise deployment of ios7 issue (help please)

Ok...here's the situation.

Gm came out Tuesday...goes live on Wednesday.

Our users...let's just say thousands are going to get it pushed via software update in their iPhone 5's.

We won't be using iTunes, just on device upgrades. ...no restores, just upgrades.

What kind of issues can we expect on 5's and iPads.

Am I worried for no reason?

How has GM worked for you.

 

No iCloud on these devices.

1st os upgrade.