I don't use it normally, but that's just by habit. I may try being a little bit less data conscious w/ it if I try since my out of pocket isn't different between the two plans. I used to be a lot more data heavy, but with WiFi going everywhere I make it a point to drop onto trusted networks because it's easier on my battery (in addition to the obvious data savings). I was using under 2GB max monthly with my VZN Unlimited plan so it made no sense to pay over 2x what I am now with ST for it and I changed.
It's solid. I went to it only because they switched on ATT LTE and have no problems. Their CS I've heard nightmares about, but I haven't had an issue. Their site freaked out and error'd during my PORT REQUEST and it billed my card 2x, and didn't port. I hit up their online person and they gave me a case and # to call. Called and within 30mins they had my port in process, 1 charge applied to it, and the other crediting back. So that particular instance was fine.
My only gripe is if you're an LTE speed purist as they appear to use a proxy that varies. I did a WHAT IS MY IP a minute ago and it was a service in FL (I'm in AZ) and another time I think it showed somewhere in CA. So they're using a proxy service which is going to cut your speeds depending on the hops back / forth / destination. Overall, though, for 45 bucks a month I have no complaints.