XXL to unlimited...I have a question

I am considering switching my five lines on XXL (+ 6 bonus GB for life) to Start Unlimited for all five lines. I have two considerations....Cost changes and service changes.

Right now my bill is $222.45 per month. That breaks down from $20 per line for access fee, plus $4.02 per line in surcharges, plus $3.09 per line in taxes, plus $17.38 per line in data (I have an employee discount that I would lose).

So if I switch to Start Unlimited, and get paper-free billing and Auto Pay, it should be $30 per line, plus if Verizon surcharges and taxes stay same additional $7.11 per line. Totalling $185.55

Is this correct or am I missing something? Because this would save me $36.90 a month. That's $442.80 a year! Pretty significant! Am I missing something?

Also, how is the quality? The little star says "Start Unlimited users may temporarily experience slower data in times of congestion." I'm pretty rural, don't think that'll happen often to me.

So what do you think? Thanks in advance for any insight.