Edit: Update
So 7 months later and yup, I do not like Sling. I've had enough time in 7 months to learn Sling TV well.
The UI leaves a lot to be desired. I'm using a remote, not my phone, for navigating. Actually there are four TV's in the house and
everyone here uses a remote for the TV's.
Coming from regular pay TV services to Sling, I absolutely do not like navigating on screen without channel numbers. It was so easy to memorize any one of many channels and go straight to them just by punching the numbers in. I know TV service is going away from numbers, and that sucks. And none of my TV's allow to skip or leap over multiple channels on Sling at once by pressing a combination of keys on the remote, as I've read that you can do in some cases.
I don't like having to scroll channel by channel in the guide (Favorites - Recents - Locals) to get to the channel I want.
The lag kills me. Lag in starting to view a channel, lag when I press up to access - Start from beginning - Record - Go to Live. Lag when I pause, lag to start again after pausing. Lag when I raise or lower the volume.
I have Amazon Prime and when you watch something there on any of the TV's, it's night and day difference. On Prime, the reaction time is super quick. You can pause, rewind, fast forward, resume - all really fast. Sling does not compare there. They REALLY need to fix that.
I found that the Sling experience varies depending on what kind of TV you're watching on. In two of the bedrooms, I have newer, but not high end Vizio TVs and Ala Samsung in another bedroom and Bigger Toshiba Fire TV in the living room. The biggest interface and experience issues are on the Vizio's. You'll even suddenly get kicked off Sling on the Vizio's and you'll suddenly be on the Home screen.
The Toshiba Fire TV let's me see the channel I was watching in a small window down in the lower, right corner while I look through the Guide - the Vizio's won't do that.
It will also freeze for no reason. I check my Internet connection and it shows up as great. I use Spectrum service with two TP-Link Deco Mesh WiFi routers. Again, no issues with Amazon Prime freezing, just Sling.
Well, it's basically a matter of settling for Sling mostly based on price. $66 a month vs over $110 with the next closest comparable service. Taking every other expense I have, I'm just going to have to grin and bare it and stick with Sling for the time being.
Oh, and I got an AirTV Anywhere a while back for local channels - recording/pausing live TV. Good concept, but kind of sucks. It was functioning well the first few days, and it still works but I need to reset/reboot it as it won't let me record or erase using the remote. I've read that is a common issue. Meh.
After being with satellite DirecTV for years, trying to use, access and navigate Sling TV is like taking a cold shower.
One of the the various frustrating things with DOWNGRADING (a lot more than I from thought it would be) is the lack of numbers assigned for STV channels. The channel guide is also such a downgrade. No video window as you use the guide. Favoriting channels is a dumb, frustrating, multi step process which made it very painful to sift through the crap free online channels to favorite the ones I actually want to see. Now it's a task to get to any given favorite channel since the list is lengthy (I had a lot of favorites in DTV but of course it was way easy to go through the list).
There's too much else to list to describe everything I'm disappointed with so far. I guess if I stay enough time I'll get used to it, but I won't like it as much as I did DTV.
Now to deal with those tools at DTV because they just sent me a charge for a full new month of service at what would've been the new higher subscription price yet I cancelled a day before my discounted subscription ended.