That's where i'm at the predicament of wanting something with 6" travel, but not a XC bike, but also, not a DH bike. Something in the middle.
Sounds to me like you have the right bike now. You've pretty much described a MiniDH/Supreme there.
Reign X = 6.8lbs
Mini DH = 9.5lbs
and the giants are supposed to be stronger.
Is that based on the few dodgy 09's that cracked though? I don't believe that the Reign can have 30% less material and be stronger. Its just not possible. Maybe its because the Mini is used for DH so has a higher failure rate, whereas the Reign is used for XC so has an easier life.
Something else to consider, would you want to ride downhill on a Meta 5? Thats the same frame weight as a Reign.
For all day riding the Reign will be better, but for downhill the Mini is a better bike. The thing to consider is that a Mini can easily be used as an all day bike but can a reign be used as a downhill bike? I don't know how seriously you do downhill, but you might find the Reign will hold you back and take the fun out of Downhilling.
The last thing to consider, for £900 you could get a pretty reasonable hardtail bike that would suit the all day rides, and you could keep the Mini for DH. That way you don't compromise on anything. Thats what I would do if I had £900 burning a hole in my pocket.