I recorded this and watched it just now, and while I could see differences, I thought it had remained true to the original. I am particularly glad that it's been made with stop-motion animation, instead of computer graphics.
It was lovely, and I hope it brings the Clangers to a whole new generation - they are a really happy childhood memory of mine, and it's nice to see it come back.
DS had to watch it 3 times in a row, nice thing to watch before bed. It certainly seemed to soothe him and agree it's lovely that they seem to have stuck to the original. DS always seems to prefer stop-motion animation than computer animation so it might be a let up from all the Raa Raa we watch!