I've had Sling since February, and I have both a Roku 2 and a Roku Stick. Seems to make no difference which TV I'm on with Sling. For the first few weeks (maybe even a couple of months), Sling was a major problem. Repeatedly "loading," received black screens for (sometimes) a minute or two, picture was often quite poor, regardless of speed setting, etc. But I guess they've done some upgrades or other work to their system because---in general---since around the beginning of summer, most of the time everything works well. But there are still some problems that occur, and I'm quite certain that the cause is Sling. I understand that download speed is limited by Sling's servers, and has nothing to do with my actual download speed for Roku in general. (FYI, my ISP provides a realistic speed of 50 at our computers, and the Speedtest app on both Rokus are usually about 20-25, depending upon test server.) Never have any problems with other channels (NetFlix, Hulu, Pub-D-Hub, etc.), and I stream sporting events on Watch ESPN and BYU-TV with no problems at all.
But these are my Sling problems---does it happen to others, or is is just me?:
1. Usually on weekends only, I can be watching a soccer game on BeIn, OneWorldSports, or UDN, everything will look just fine, great picture, and then---simply does an autonomous reboot. Screen goes black for 10 seconds, then it reloads Sling, and goes back to the channel that I had been on. If I was watching live TV, I'd only miss about a minute before it's reconnected. But if I'm watching a recorded (or delayed) program, it, of course, returns to the live feed. Thus, if it's recorded, I need to go back to that program, and 'step through' up to the point that I was at before the reboot occurred. On a delayed program, if I was watching the first half and it reboots back and connects live in the second half, then I've already seen the score and it ruins things for me. As noted, I've tried to keep track of when this happens, and Monday to Friday, rarely if ever. But Saturday and Sunday---likely prime viewing time and busy Sling servers?---this happens repeatedly. Yesterday, it happened during the KHL hockey game on OWS, and twice during a soccer game on BeIn.
2. Sling speeds vary from time-to-time, which causes the picture to degrade for a period. I normally have my settings at "High," up to 2.8Mbps, and when I check speed at that setting, it mostly stays at 2.6Mbps. But for brief periods, the speed will slow down to under 1.0, which causes a fuzzy picture and messes with text (score boxes and the like) so that it's almost unreadable. This happens most any day, but more often on weekends. Not a major problem, because it usually only stays that way for less than a minute, then restores.
3. On-screen program guides. Maybe on entertainment channels the guide is accurate, I rarely watch one of those channels. But on sports channels such as BeIn, OWS, and UDN, the program guide is often wrong, both content and time. I have a tablet next to me with a TV programming app (I use Zap2It, but there are others), and the information shown on it is about 99% accurate. And it's not that the channels are making last minute changes---I can look at the schedule of upcoming games on my tablet days ahead and it's accurate, so why can't Sling program their on-screen guide to have accurate info?
I don't call myself an expert, but IMO all of the above items are Sling problems. I read something a while back that Sling tries to 'spread service' across servers during busy times, to try and keep decent signals during busy times (like weekends), and I'm thinking that they need to add more servers or upgrade existing ones to handle more traffic? And maybe consider an improved method of populating their on-screen guides?
Not going to cancel Sling anyway, because there aren't alternatives for online viewing of the games I want to watch, but I'd like to see Sling commit to ongoing improvements!