I have never used VZW apps when I was on their service and personally don't know what that messaging app is like but I bet it is restrictive when it comes to customizing the appearance.
I personally use Hangouts as 1) I don't care about that whole NSA crap; b) I like having my hangouts conversations mixed in with my texts, easier to use one app instead of 2+; & c) I like the archive feature for texts + hangouts. Makes it easier to keep my inbox (or whatever you call it) cleaner.
The other texting apps I've used don't have that and I end up losing texts..because I accidentally delete them because I'm so used to the archive feature with hangouts. I've used the stock messaging app on Samsung devices (it is alright, customization isn't that great), ChompSMS (I like this customization better!), & MySMS (so I can text on my computer without needing my phone around; plus is backs up my texts to my email + Evernote + Google Drive).
I've also got MightyText working in the background constantly to backup my texts to the cloud and so that I can text on my computer. This one is a lot better when it comes to texting from your computer. I'm not sure if it works with Mac because I use a PC BUT it tells you your phone battery life, it
can back up your pictures + schedule messages to send (if you get the new pro version) & Manage your contacts from the web app. It's awesome.
http://mightytext.com
I tried handcent a while back but ended up deleting it before I even really used it. MySMS & ChompSMS both have the popup messaging where a window will popup allowing you to read any new messages and reply without actually opening the app itself. This is one thing I miss from Hangouts but I can live without it.