Cabel Sasser notes the limited resolution, lag, and MPEG artifacts when using the adapter:
There’s a lot more going on in this adapter than we expected: indeed, we think the Lightning Digital AV Adapter outputs video by using AirPlay (or similar MPEG streaming).
The adapter apparently has an ARM system on a chip with 256 MB of RAM. It doesn’t work right away when you plug it in because you have to wait for it to boot.
Commenter Apple Neednotknow:
From talking to a friend from Apple last thanksgiving, this was done because of the lack of pins, and the iOS device starts by pushing firmware to the dongle then streams video to the dongle which outputs the hdmi signal. The dongle and firmware combo were described to me as basically an underpowered Apple TV minus the wireless hardware.
Commenter Common Sense:
This is pathetic. We thought the lack of analog audio line out was a major blunder, but this is just unbelievably bad. Reasonable people could understand that Apple needed a new dock connector, but that would be to provide BETTER signals, not worse.
The idea is great: The lightning adapter will be Apples only port and it will remain future proof.
In reality however, the lightning connector also has a limited bandwidth thus they have to compress their data, the conversion to and from the Apple lightning protocol requires lots of processing power, on both sides, and reduces quality. And finally it’s expensive.
On Reddit, thisisnotdave writes:
The Lighting Digital AV adapter does in fact do 1080p for video playback! It DOES NOT do it for screen mirroring, which suck, but its important to make that distinction since neither OP nor the article do so.
The lightning connector and cable can all support huge amounts of bandwidth, at least USB 3.0 levels, but the NAND controller in the current batch of iDevices can’t. The connector itself is pretty future-proof, though.