Have any MTB mags done their big hard tail tests yet this year? MBR do a hard tail of the year, but I suppose you'd need to look at the 2016 one. The good thing is £1k gets you on a nice hard tail.
Where can you use your voucher apart from Evans? I would at least have a look at Boardman as the £1k will go a lot further. I also am a fan of Evans' Pinnacle bikes for their value. I have a Pinnacle cyclocross bike and it is very well made. I've ridden it 4400km in a year and it takes so much abuse. I would be happy on a Pinnacle MTB too. For example:
https://www.evanscycles.com/pinnacle-iroko-2-2017-mountain-bike-EV275644
More I look at the Boardman and read reviews the more I'm liking it. Will probably be a while until the voucher is delivered, but think I'll go for this. Great spec, and rides well and actually probably suits the majority of the my riding up on the downs.