However, I read that I can't rewind live TV? And the longest I can keep DVRed programs is 90 days? Those are big issues for us.
Well, the first concern can be addressed with hardware -- just get the AT&T set top box. The second one is more problematic.
Yeah, one of the big things going for AT&T TV is that it has channels from all the major groups, unlike YTTV or other streaming cable TV services. (Although keep in mind that AT&T TV, unlike YTTV, still lacks PBS and NFL Network. And in many areas, it lacks the local CW station.)
The 90-day retention limit on AT&T TV's cloud DVR is unfortunate. That's way shorter than any other competing alternative. They should extend it to a full year, or at least 9 months, same as YTTV.
Who knows what may happen soon with the service. This month or next, AT&T is supposed to complete a spin-off of their cable TV services (AT&T TV, DirecTV, and the no-longer-sold Uverse TV) to a new separate company called DIRECTV. lt looks very likely that AT&T TV will be rebranded as "DIRECTV STREAM," a name which they trademarked last fall and which has begun replacing a few instances of the AT&T TV name on their customer support site just this week. Perhaps they will make some changes/improvements to the service.
One thing to expect is a second-generation streaming box, which was just submitted to the FCC for approval last month. I'd say it will be ready to go as part of the pending relaunch just around the corner. (My bet is that we finally we support for live 4K HDR content added to the service at that point too, maybe in time for the Olympics.) Someone on reddit posted that AT&T TV is currently working on the ability to pause and rewind live TV in their Roku and iOS apps (no idea if that's true though). So perhaps the app will soon come closer to feature parity with their box.
Anyhow, for anyone thinking about signing up for AT&T TV or buying their optional box, my advice would be to hold off for the next few weeks and see what pops up.