It can be very difficult to weed through the sales pitches vs real experiences. Someone recently wrote a quick review of what they've tried, and I found it helpful. I use an android box, and my review applies to that mostly - except for smoothstreams where I tried everything.

So far, there are only two services I would recommend:

IPGUYS - Most reliable. This is my secondary provider. The Good: If you want IPTV that just works, this is the one. It had the fewest channel issues (audio sync, black screen, etc) of the services I've tried. Great selection of channels, including movie channels. Almost no buffering / stuttering. The Bad: Quality isn't the best. HD channels are compressed heavily, and don't look HD. Not great for sports. Even some common sports channels are only SD.

Voodoo - Best Overall. This is my main provider. The Good: Great quality HD. Channels in HD, look like HD. Some 4k channels, although I don't use them, so can't comment on that. Most sports channels are in HD. Catch-up tv goes back like 48 hours, and on a very wide selection of channels. Makes it great for watching movies on the movie channels, or your favourite sitcoms the day after they air. Very little buffering or stuttering. The Bad: Some channel glitches. DIY network has had no sound for a week now, main HBO channel is blank, a few channels had audio sync issues, etc. Guide is laid out a little unusual, and channels are duplicated in various groups.

The Others:

Flawless TV - It's Pretty, but broken. I never really got this service to work reliably. It had great quality HD. Fast channel changes. I was using it on android box with perfect player, which made it look amazing, but this really crappy glitch would happen where it would just jump back 30 seconds and replay it again. It would happen a couple times, then just jump ahead 2 minutes. Made the service unwatchable. Trying to watch NHL center ice games was impossible. Buffer city. Best guide experience in perfect player though. Really wished this service would have panned out.

IPTVSUBS - Jerky. For some reason, most channels seemed to stutter. Not buffer, just stutter. Like a little jerk in the picture every second. Other's may not notice it, but it hurt my brain. It wasn't smooth. I can't even comment on the rest of the service because of this. I tried the service in two different months, to see if it was just an issue I had at a point in time - and it wasn't for me. Your setup may be different, but for my android box, it was a no good. (tried the android app, which I hated, and the stbemu)

Smoothstreams TV. Ugh. Ok, I get that people love this service, especially sports peeps, but I couldn't handle the fact that it's really only a live sports service, and many of the channels flip to live sports during peak sporting times. For example, if you wanted to watch the FX channel, it may be showing soccer. It's NOT for casual couch surfers. It's sports. This would be ok, except even the sports never worked right for me. While watching the MLS Cup last month, I was constantly getting kicked out of the kodi app every 5 or 10 min - on the hd and non-hd feed. Same goes for android/Chromecast. And the web browser player would just drop after 5 to 10 min too. The plex channel was hard to use, and never worked right either. It just made the experience miserable. Trying to watch hockey returned the same results. One day it would work, next you would be getting kicked out. That said, lots of people appear to love it, just didn't work reliably for me on my android box, chromecast or computer.

So far, if I were recommending a service, it would be voodoo and ipguys.

EDIT: I should add that using an actual mag box may yield different results. This is just based on my experience with an android box.