Hi @zaku49 and welcome to the Community!
If price per GB is one’s criteria, there’s no denying Mint offers attractive pricing. I’ll also concede, Mint is able to support phones Republic is unable to though since the launch of its 3.0 platform in 2016 Republic does now support over 70 phones.
On the other hand, Republic offers things Mint does not. Mint offers no roaming of any kind. If one travels to a location where T-Mobile lacks coverage, one’s phone won’t work. Republic does offer domestic voice but no data roaming.
Additionally, unlike Mint, Republic offers more than one coverage option for many of its compatible phones. Republic provisions cellular coverage with one of two network partners. One partner operates a GSM network and is T-Mobile. Republic’s other partner operates a CDMA network and is the now T-Mobile owned Sprint. Though T-Mobile and Sprint have merged the networks remain separate. Cellular coverage is provisioned with one network or the other not both simultaneously.
Republic also offers value added features such as spam call blocking via the Republic app, its Extend Home adapter, (which allows one’s Republic number to be shared with handsets typically used with traditional landline service) and a favorite of mine Republic Anywhere albeit Anywhere is no longer being currently developed.
Price is certainly a component of value, however, it’s not the entire picture. Folks want different things out of their mobile phone service. For me, Republic offers value at a price I find fair.
I’ve experimented with Mint and unfortunately had a poor customer service experience. Finally, I find this Community to be part of Republic’s value proposition. Mint has a forum but it’s nowhere near as robust as Republic’s.