Audio Sanctum, the sole XTZ dealer in the UK appears to have stopped trading. However, XTZ's philosophy remains unchanged, although you might need to visit their website to find out how you can buy and try without risk. AS offered a three week home demo, but as XTZ are based in Sweden, returning to them makes it a tad pricey if you don't like them.
Check out Techradar and possibly the Hi Fi World website who have both reviewed, rather well, the 99 series range. Great company, IMO, and well worth investigating assuming you can get round the return to base if you don't like them.