My (New) iPhone Data Speeds vs Friends exact model/carrier

[vitaherb]

Just signed up for verizon yesterday on their unlimiited data plan and upon installing apps/browsing internet I am getting beyond terrible results. I proved it's not a 'dead zone' by having a friends exact model/carrier come by and test them out side by side.

I bought this phone off craigslist in "mint" condition from a cool guy that I contacted and he insists it's fine and even offered a refund- it is still under warranty as well. Could this be hardware? Or something SIM/network related? Any insight would be great, we all know verizons phoneline.. Got me nowhere today!

http://imgur.com/a/IB1fR
http://imgur.com/a/ehnV4
http://imgur.com/a/IB1fR

There are photos of the tests, any insight would be great.

 

[Audit13]

Since it's under warranty, take it to the apple store for diagnosis.

I did just that with a gsm iPhone 6s because I seem to be only getting the bars on signal while an iPhone 6s plus was getting 5 bars.

Turns out my phone is fine and download speed is excellent even with two or three bars.