All I can tell you about is the roaming charges.  Before we got the cellular
repeater, we could jump from home signals to roaming in our own house.

We have yet to pay any roaming fees.

If you do change plans, make double damn sure you have the right account
number when you pay your bill.

We just went through a real fiasco with billing when they changed account
numbers on us due to a discount plan that went into effect a month after we
started service ( nothing else changed and this discount was applied for
when we signed up as new subscribers).  The paper bill they sent had the
original account number and that is what I had set up for electronic bill
paying through my bank.  My wife got a call one day that if they didn't
receive payment soon, we would lose service.

What a mess.  They had cashed the check but didn't know where to apply it.
My wife called them and spent considerable time with 2 different people
trying to sort things out.  Finally they found out what happened and
credited the account.  The next day I got a new paper bill with the new
account number.

It would have been really nice if they had mentioned at any point that
applying my wife's discount would change the account number for billing
purposes.

The vision feature is $15 per line if you wish to add it.  This is as
of October 1st.  Before that date if both of you wanted the vision, one
line would have paid $15 the other would have paid $7.50.
Unfortunately this is not an option now so if you both want it , there
will be 2 $15 charges.  Vision service does not include text messaging.
You would still pay .15 each for those.  They do however have 3
different text messaging features.  $5 for 300, $10 for 1000 or $15 for
unlimited.  Like the vision this is a per line option, so if both
wanted 300 text, youd pay an extra $10 total for the 2 lines.  As for
roaming, the new plans for the most part include roaming anywhere in
the USA, Puerto Rico, US Virgin Islands, and Guam, digital or analog.
However there are some areas where the free roaming is not available,
so you will need to ask about this when you call to change the plan as
it is dependent on what they call your CSA, which stands for Customer
Service Area.  I hope that explains it thoroughly for you.

A friend on the inside :-)