Cube reaction 20 or 30 speed?

gazcarsf1

Looking to buy a new cube reaction, narrowed the choice down to the hpa sl(alloy) or the gtc race (carbon)' problem being that the hpa is 30 speed and the carbon 20 speed, and I am not sure if the 20 speed will have enough gearing for high speed xc blasts? The bike will be used for local xc blasts and canal, cycle paths etc, with the odd trail centre blast in between, I have a canyon spectral for normal trail use. I have also been looking at the canyon Grand Canyon cf 5.9. Any thoughts guys
links below

http://www.cube.eu/uk/bikes/mtb-hardtail/reaction/cube-reaction-gtc-race-29-carbonngreen-2015/
http://www.cube.eu/uk/bikes/mtb-hardtail/reaction/cube-reaction-hpa-sl-29-black-anodized-2015/
http://www.canyon.com/en/mountainbikes/bike.html?b=3690