Buy the Ethernet port first
If you take one thing from this page, take this: a wired connection to the television removes more IPTV problems than any other change available to you, and most streaming sticks cannot accept one without an adapter. A modest box with a network socket will outperform a considerably faster stick on Wi-Fi in the room where it matters.
This is unglamorous and it is the whole game. Live streams are not demanding in bandwidth; they are demanding in consistency, and Wi-Fi across a house is where consistency is lost. Any comparison that ranks devices on processor speed while treating the network socket as a footnote has ranked them on the wrong axis.
Sticks against boxes, and why the cheap stick fades
A streaming stick hangs off the back of the television in still air, and the small ones throttle when they get warm. The familiar pattern is a device that is perfectly good for twenty minutes and begins stuttering an hour into a match, which people reasonably but wrongly attribute to the provider. A box sits on a shelf with room around it and does not do this.
Sticks are still a sensible starting point when the budget is tight, and the better ones are genuinely capable. But if you watch long live events, which is most of the reason to have IPTV at all, the thermal argument alone justifies the step up to a box more often than the specification sheet suggests.
Memory matters more than processor speed
Channel lists in this category run to thousands of entries with a programme guide attached, and that is a memory problem rather than a computation one. On a device with too little, the player reloads the guide constantly, channel changes slow down, and the app is killed in the background when you switch away. More memory is what keeps a large lineup usable.
Video decoding is the other hardware question and it is mostly solved: any current device handles the formats live channels are delivered in. It becomes worth checking specifically if you intend to watch 4K, and the requirements guide on this site covers what that needs beyond the box itself.
The operating system decides what you can install
This is the constraint that catches people after the purchase rather than before it. Android-based devices, which includes Fire TV, Android TV boxes and Google TV, let you install the full range of players, and the strongest software in this category is Android-only. Apple TV is capable hardware inside a closed store, so the choice of players is narrower.
Roku is the case worth naming explicitly, because it is a common household device and the usual advice does not transfer to it: it does not permit sideloading, so most of the players people recommend simply cannot be installed. If IPTV is part of why you are buying, that is a decision to make before the box arrives, and the player comparison on this site sets out what each platform actually allows.
The very cheap unbranded boxes are a different product
Generic Android boxes sold under names that change every few months occupy their own category, and the risk is not merely that they are slow. Devices in this class have repeatedly been found shipping with modified firmware and preinstalled software nobody asked for, and there is no update path to fix it because there is no manufacturer in any durable sense.
The saving is also smaller than it appears once the device is throttling within a year. A box from a manufacturer that publishes updates, from a retailer you could return it to, is the floor worth staying above, and it is not an expensive floor.
A remote you can live with is not a trivial detail
You will use it every day, and channel-surfing a large lineup exposes a bad one quickly. What matters is whether it has proper directional control and dedicated buttons, whether it uses radio rather than infrared so it works without line of sight, and whether the buttons you press most are reachable without looking.
Voice search is largely irrelevant here, because it searches the platform's own catalogue rather than your channel list. Treat it as a feature for the rest of the television's life rather than for this one.
What not to spend money on
8K support has nothing to feed it, since live channels are not delivered anywhere near that. Large internal storage is for downloaded content rather than live streams. And the premium tier of any device family is bought for gaming, high-end home cinema and recording rather than for watching live television, which the middle of the range does perfectly well.
Spend the difference on the network instead. A cable to the television, or a better access point in the right room, buys more reliability per dollar than any processor upgrade, and it is the recommendation almost every hardware comparison in this category leaves out because there is nothing to sell you.