Heads-up notifications are customizable.
Delay sending for proofreading
Reply from lock screen
List mobile contacts only option
Auto night and day mode
Set group messaging to replies only come to you individually
Works with my s3
Schedule a message (also available on stock)
Works with edge lighting
Developer keeps updating and responds to and fixed issues quickly, doubt Samsung does that
Supports live messaging
Send and delivered confirmation is done on the texting app, not a separate notification I have to clear.
Can set to auto close keyboard after send
These are a few of the reasons I prefer Textra over stock. It has the right amount of customizations without a lot of bloat. Verizon messages+ has a lot of useless bloat IMO, and over the years I've had more issues with Verizon messages then I have had with Textra, and Textra issues have been resolved a lot faster then Verizon messages, and there was an issue with Verizon messages where messages were not sent to certain numbers, took forever for Verizon messages to fix it. Textra developers keep this app updated and respond to your questions and ideas, they implemented one of my ideas in one day. Textra is worth every penny I paid for it, best app I've purchased.
In the end, it's what works for you.