Lag is not really an issue on most popular devices. If all you want to do is IPTV, the Firestick 4k works great. I have 2 of them. No lag at all running anything. It's pretty quick but if I had to recommend one of your choices it would be the shield. You can't go wrong and it's open source. Apple is the opposite of that.

shield / tivimate user here.. No issues and couldn't be happier. But we use the shield for more than just tivimate and it handles everything we throw at it. If iptv is your only goal you can achieve that goal much cheaper than either of your options.

Shield Pro. It's the only streaming device I haven't had to replace since I bought it in 2016.

Have both definitely go shield.

Over past years I have had many different boxes and many different issues. I have 3 boxes left and they are all Shield box style. All work very well and auto update often. Only lagging or time out issues was directly related to my network wi-fi signals. My fix was to directly hard wire all boxes via Cat6 Ethernet wire to router. Works flawless. Also love ease of attaching USB external storage. Can drag and drop files from PC file to Shield file rapidly. I also use Rii mini Bluetooth keyboard mouse devices with no issue. Also use a Shield As a Plex server in my office. Get the Shields.

Nvidia Shield. I have the tube though and I find that powerful enough.

Get a Sheild they are the best at everything, my son has the new Apple TV and it’s also great but steer clear of the Amazon 4K stick or Cube they are mince

I have both for different TVs. If you have all Apple devices and will take advantage of things like Airplay then the Apple TV with GSE for viewing IPTV is a good choice.

If you don't use Airplay or use a combination of Apple and Android the the Shield a better device. It is really fast and you can use Tivimate which is better then anything the Apple TV has to offer. Shield can also be used as a retro game console or a media server.

Shield all the way!!firestick 4k with ethernet connection works well allso

When it's really just for IPTV, I wouldn't choose either one at all. It's overkill. Choose a Mi Box S, install TIVIMATE on it and enjoy

The shield 🛡 easy choice . If price is an issue check Facebook market place in your area.I bought one for my mom and dad super cheap .

I have tried Shield (TiviMate), Apple TV 4K (iPlayTV), Fire Stick and an Android box at home for IPTV.

Of the platforms, I have been most impressed with Shield and Apple TV. Shield is an excellent, flexible platform that does a lot beyond IPTV. But as a "consumer experience" our household prefers the Apple TV. It is easy to set up and use, with a great interface. Shield with TiviMate works well, but is somewhat less easy to use for the average set top box user.

The Apple TV is easier to set up for non-domestic streamers, but that isn't strictly an IPTV issue and not what you asked about.

No one mentioned the most important reason for the shield: DLSS. It's magical, turns your 720p high Bitrate streams into 4K.

We used Apple TV for sometime but it doesn't have the options to do what I'd like. Moved on to a Firestick and a Cube, but always had issues. Purchased a TIVO Stream 4K, USB-USBC cable and a 32gb stick and could not be happier. Does everything I need and have enough memory I'll ever need. Very happy with this set up. Next step up will be to the Shield Pro