My brother owns one of these where as i only own a normal standard 20GB premium. I play on it from time to time and i think they are much better than the original premiums. They're much smarter looking and quieter.
The HDMI is also another great feature included in the console. The price is excellent as always with play.com
There aren't many more features to the premium other than HDMI, but for the price differece its all worth it. They have a lower chance of breaking. i.e Red ring of death. These are much more reliable and actually feel much smarter and you feel as though you've got the best package around. The black finish makes this console real smart and the added 120GB hard-drive is more than enough. But its better to have more than enough. I would reccomend this to anybody looking to buy an Xbox360 and tell them to pick this one. It may be the most expensive, but it's all in the package that you get. Also this comes with a 'GOLD PLATED' HDMI cable. Not a cheap one, this is excellent as Sony do not put a HDMI cable in their box at all. Which i feel is very disappointing as you are not able to use the HDMI straight out of the box unless you purchase a seperate HDMI Cable. I would reccommend this to anybody wanting to buy a 360 and tell them to get this. Not one of the lower graded cheaper packages. Its very cheap too compared with the PlayStation3, around a £100 pound price difference. So to you people out there reading this review, buy this if you're looking for a 360. I suppose that this has its up-sides and down-sides but these down-sides are extremley minor and will not affect your gameplay.