What makes the difference? Mostly it is the songs themselves. On a great record with many great songs, an occasional merely good song sounds just fine. On a good record with only a few great songs, the merely good songs start to rule the day. And there you have it. In the case of Sloan, it is perhaps arguable that some of their good records suffered slightly from recording or production differences that their great records did not have to work through. But it's mostly the songs.
Sloan have all the essential elements associated with great bands. As I've mentioned numerous times before, great bands need a great drummer (Andrew Scott more than qualifies), a good singer (Sloan has four), and a good songwriter or two (again, Sloan has four). They have recorded thirteen original studio records, and none of them are less than good. But the great ones still stand out as records you can listen to from start to finish without even a whiff of disappointment.
There's a bunch of reviews online already that you can use to help you dissect this new record. But all you need to know is that if classic rock and power pop are your bag, Sloan firing on all cylinders is the obvious answer. Great songs, great harmonies, solid lyrics, melodies and hooks abound.
So which ones are great and which ones are "merely" good? The good ones are Smeared 1992 (a solid debut but still clinging to a post punk sound that gets tempered as they mature), Pretty Together 2001, Action Pact 2003, Parallel Play 2008, The Double Cross 2011, and Commonwealth 2014 (which suffers more from the concept than the execution). Most of their 2000s records just don't have the consistency of their 90s output, but there's room for plenty of opinions if you happen to be partial to one of these.
The great ones are Twice Removed 1994, One Chord To Another 1996, Navy Blues 1998, Between The Bridges 1999, Never Hear The End Of It 2006 (an amazing thirty songs in 76 minutes), 12 2018, and Steady 2022.
Any band that can rack up seven classics in thirty years is an impressive band. That the same four guys have been there the whole time is pretty amazing.