33rpm vs 45rpm - which is better

In theory, the higher speed pressing should sound truer to the master, as with tape speed. 15 inches per second sounds closer to the source tan 7.5 ips. But with records, you may not want to have a 2 record set or get up every 10 minutes to turn them over. Personally, I prefer 33.3 pressings in general. Or if you love the music that much, just buy both for fun. Plenty of people have multiple copies of the same recordings 

45 RPM records are more dynamic and seem to have lower distortion levels. The only problems are, you have to turn them over more frequently and whatever noise is on the record occurs at a higher frequency which makes it more noticeable. Quality pressing is vitally important. 

+1 @mijostyn 

The highest quality audiophile recordings I have are 45 rpm… typically causing one disk to need to be split into two… and requires flipping disks at a ridiculously short interval. But they do tend to be more dynamic.

I was taught by the various audio magazines that 33rpm LP was the best available format for sonics, and yet when a friend bought round his 45rpm 12 inch single of Duran Duran's 'The Wild Boys' the dynamics were something my Linn/Naim system had never before conveyed.

In fact I can't recall hearing a poor sounding 12 inch 45rpm single. Therefore my vote goes to the 45rpm.

Sonically the 45 should be superior to the 33 1/3 pressing especially if mastered by Kevin Gray. And personally, I wouldn't buy an orange record.