If you want a lighter, racier bike, the KTM Aera Comp is staggeringly good for the money! In fact, all it really needs to be a pukka race bike is a slightly lighter set of wheels, not that the Shimano/Mavic wheels on it are bad (far from it) mind… Comes in 29er (faster) and 650b (bit more nimble maybe) flavours and if you are quick, there was a 2014 model left in stock at the distributors in a 19″ that one of the mags tested for 3 weeks that they were chucking out for a mere £900! Even at the full £1449 it’s a ridiculous bargain mind…
If you want a slacker, meaner trail weapon, the either the Whyte 901 or 905 is the way to go. Though neither is heavy, they’re definitely not XC race bikes as the geometry is pretty radical, but they seem to astound anyone that slings a leg over them! Certainly a proper hooligan of a bike for mixing it up with full sussers.
Why a no to 29ers though? There’s plenty of fantastic 29ers at that price point that will really blow the preconceptions about the larger wheel size away, such as the Kinesis FF29 and the Whyte 729.