I've been using Handcent for a while now, just got the HTC One about a month ago, Motorola Photon prior. Handcent has worked well for me with little problem. While the stock messaging app is fine a necessity for me was repeat reminders of a received message, in case I didn't hear/feel it the first time. The ability to change the notifications (icons, vibrate and sound) based on contact is important to me (work overtime, etc.) I haven't used Textra so I can't comment on it, but did use GoSMS previously and it just became too bloated and uncomfortable.