Just finished the first season, and tbh I thought it was mostly great.
The only problem I have is that there was a glaringly obvious rewrite in Homelander's portrayal. The first season went to great lengths to portray Homelander as, as far as anybody knows, a very straight-laced all-American Superman-esque hero, with even Butcher noting that Homelander "is the exception" to the other heroes who are more degenerate and personally unlikable (which is odd, given his motivation). This characterization of Homelander as the only famous hero who is really a hero is meant to make the scene at the end of the episode where Homelander destroys that Baltimore dude's plane (with his twelve year old or so son inside) all the more shocking, and it works for a while.
But then, almost immediately, his characterization becomes more openly and casually antagonistic, crass, and bullying, with him barely making any effort for the facade for most of the show.
It's not a huge issue because the actor kills every scene he's in and is able to make the switch from charismatic patriotic hero to cold and calculating sociopath jarringly effortless, but it was still noticeable.