The good:
Literally everything good, of any weight in Han Solo's life seemingly happened across a week some 9 years before ANH. Convenient, otherwise you would have to go through more of these.
Having said the above, Solo in this movie is not the cynical, scoundrel, pressure cooker Han Solo we know. It will take at least one sequel to explain what made him so.
At times the movie feels as if a lot of good footage was cut out, other times it feels as if it's a shortened version of some long, slow pace TV show, but generally it's hard to understand what drives the characters you are watching and they are often full of contradictions.
We don't get to discover why Einreicheinfuhrer is wearing Nicolas Cage's dead ferret wig on his head instead of Han Solo's hairdo. So there are more mysteries for sequels.
We do get to discover that Zorro, Superman and Lando have the same obsessive compulsive wardrobe penchant, apparently.
Turns out Kessel Run in 14 12 parsecs has the laziest, easiest, paint by number explanation. We all know by now that parsec is a measurement of distance, not time, but although there may be literally better speculations on forums, even on this forum, then what was provided - you don't have to wonder about that legend anymore.
Comedic robots, they weren't always funny. Turns out.
As others already have said - fuel. It is a thing.
Soundtrack doesn't exist, on any level. Disney saves you money on OST again.
There are at least two OT camoes, but not how/what you expect.
The bad:
Absolutely nothing, of course (awaits high 90% rotten tomatoes score).