Edit: should've looked at the link dammit. Mine is a pressure keg, totally different looking to this - more like this:
http://www.bigboystoys.co.uk/products/king_keg_personal_brewery_bitter_-_save_£20.html
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I got one of those for xmas, and whilst i had some initial problems (pressure valve was leaking, didn't have it hot enough to start with, took 6 weeks instead of 3) I produced a very nice first batch, the general consensus from all who tried it was "Much better than I thought it was going to be - a bit like a dark belgian beer" which I thought was funny cos it was an english ale!
Anyway, since then I've bought a 25litre fermenter, and have fermented a new brew (irish ale) and racked it into the mr beer keg (mine is called a Microbrewery King Keg - same thing I think) and it's currently in secondary fermentation. I learnt from the mistakes and it's much warmer than the first time, and it seems to be doing well from the few ozs of beer I pull out from time to time.
If space is an issue, then the king keg is very handy in that it's quite small and can be tucked away in a corner somewhere. Also there's no more time investment needed than the first setup - no racking off midway through the brew. And it's a very simple intro to the process. I'm glad I got mine, and have now expanded my empire slightly with some more kit.