The Pixel 2 XL also does SRLTE all the time. The big downside seems to be that SMS always uses CDMA again instead of using IMS. So long messages will be split, incoming ones are out of order (and delayed a minute or 2 sometimes), and sending takes a while. Otherwise, I suspect incoming calls will be more reliable.
Technically Sprint has surpassed Tmobile in network quality just not actual coverage. But I’m hearing it’s also some LTE expansion in this. As both the CEO and COO have stated “cell sites in new areas” in some interviews. Don’t get me wrong extended LTE is cool. But it’s still roaming at the end of the day. I would rather them fill those extended LTE areas with native LTE.