Oh fuck yes. I rented a bad quality VHS of this years ago from a local video store and was utterly blown away. I was already familiar with Quatermass from having seen Quatermass Xperiment and the British film version of "Pit", but this was amazing. Legitimately creepy and surprisingly atmospheric. Brilliant storytelling in the classic pulp vein. The quality of this print on YT is amazing.
I've submitted the cinematic version of this (Five Million Years to Earth) and it never made it out of the hopper. Both are great, however this is superior. That said the movie scared the crap out of me - and agreed, the concepts (later touched on in 2001: A space Odyssey) were way ahead of it's time.
Quatermass always had a great creepiness to it, the alien in our backyard concept. Doctor Who's producers liked it so much they stuck the Doctor on Earth for four years and did riffs on the idea.