I think The Mandolorian is utterly brilliant.
Firstly, they got the look and feel spot on - it's got the angular, scruffy, weighty look that the original trilogy had. The characters, although not the most in-depth, are all well done and feel part of the universe.
There's plenty of fan service - OK, there's a metric **** tonne of the stuff and your mileage may vary on how much you enjoy that - personally really like it (I geeked out like a bitch this week )
The storylines are interesting enough, with some great 'villain of the week' episodes all contained within an overall story arc. The nods (more like neck-breaking headbutts) to the western genre are great if like me, you enjoy that genre - Sergio would approve I'm sure.
The most important thing for me though, is that every time I watch an episode I do it with a smile on my face. It takes me back to old Saturday/Sunday afternoon shows of my youth like The A-Team and Airwolf but wrapped up in a contemporary Star Wars world. Even the outro graphics (beautiful) remind me of the old weekly shows where freeze frames from the episode were used as a backdrop to the closing credits.
This is the Star Wars universe that gave me such a rush at age 6 and imo it outshines everything made since the original trilogy (I like a lot of the newer trilogy and the spin offs, but they haven't given me the same feel).
Favreau has done a superb job - let's hope he can keep up the quality.