Its ok, but the CO2 cylinder you get with it is only 72g if I remember rightly. That aint gonna last long at all! Especially on a 250lt tank! And its a bit expensive too. I got a whole system, with pub type cylinder, diffuser and reg for around 85quid, and it'll last years before needing a refill. eBay is your friend when it comes to CO2.
Check my sig for a link to thread on pressurised CO2.
Sam