Hi, Got mine this morning so thought I would add my own review.
Agree with OP, much smaller than I expected, making it very portable. Will upload some pictures shortly. Its made of plastic, but has a good weight to it, to make it not feel cheap. The box it came in was rubbish though!
To clarify questions I originally had -
It needs a WiFi connection to work
It needs to be plugged in to a power supply. Cable Provided
It uses HDMI. Cable provided
Minor lag after initial start up, but then ok.
Quick Buffer rates.
At the minute (I've only played around with it for an hour or so) but my feelings are its OK. I'm not blown away by it just yet and here is why.
Didn't want to connect initially despite me following the 5 simple steps to the letter. They really are simple so might say something about me! To the point I was going to send it back. Eventually though it worked, although i did exactly what I had originally. (Thinking it through it may be due to me having several broadband connections in my house, it may have switched midway through pairing)
As OP said, the first minute or 2 you experience random lag for 1, maybe 2 seconds at a time, after that its all good.
If I am playing a video, i cant see it on the phone as the image freezes on the first film image, although it plays fine on the TV.
It didn't want to work with MX PLayer, so had to use stock for viewing recordings and downloaded videos.
I don't have any "True" HD content on my phone yet (700mb stuff ;P), but this highlights the lack of quality that you don't originally see on the phones screen. Netflix for example, although picture is good on the phone, it is clearly a "stream" on the TV as the image is pixelated slightly. ESPN goals is the same (although on phone its not great, on TV is clearly worst).
If the phone content is in HD, games etc (I assume same with films), it looks sweet, and ignoring the start up lag it works really well for games.
In summary (and I don't want this to sound like im knocking it), I think it is more of a party piece, rather than a day to day item you would use. Great for sharing pictures or videos you have taken with family/friends rather than them passing your phone around the room.
Its very quick, images/video buffer very fast and play within seconds. Apart from MX Player, everything I have asked it to display on the TV it has, so there are no copyright restrictions that I can see at this stage, unlike AppleTV.
A perfect accessory for those that travel alot or spend a lot of time in hotel rooms.