"And this is why Vol. 4 is the perfect sequel to a relatively consice classic like Master, especially before releasing brilliant masterworks of early progressive metal in '73 and '75. This would be Sabbath's last "doom" album for a while, I guess, and it's a damn fine note for Iommi to leave off with for a while, before eventually returning to his signature chunkiness (in my opinion, he did that on Mob Rules which I think sounds bigger than the first Dio-fronted album). This 1972 effort has been called inconsistent due to tracks like "FX" and "Laguna Sunrise", but honestly, sequencing matters very little by today's standards - Sabbath have so many classic metal songs so just throw ANY of the seven heavy metal songs here in a playlist with all your favorites from albums before and after this one, and you're set - there is actually a larger portion of metal to be heard here than on Master, and I'll say that despite that one being my preferred Sabbath outing. Even if you're reviewing this from a vinyl standpoint, there's still 11 minutes worth of the signature Sabbathian heaviness before a piano ballad (not as good as "Planet Caravan" and "Solitude" I'll admit) and a filler track enter the fold. Plus, the groovy-as-hell "Supernaut" closes out the A-Side, so there's no point complaining. "Tomorrow's Dream" is a classic shorter song as well that balances nicely between the chunkier heaviness mentioned from the previous track and a truly unforgettable momentum, with a cool pull-off riff in between the verses that emphasizes the lower C standard tuning. You can do a lot with that sort of power-chord progression and Bill Ward's drumming makes it extremely catchy in this case, as well as brighter sounding than it should be due to his use of cymbals. Ozzy also displays a little more range here and you get a sense of the charisma he's known for as a frontman."

- Mercyful Trouble, metal-archives.com