The first two episodes were unbearable. They weren't bad per se, but just so slow. I watched them in 1.5x, otherwise I wouldn't have made it pass them. There was just a lot of unnecessary scenes that took way too long, especially fight scenes.
Someone wrote that Jack and joker is trying really hard not to be just a BL and it shows. I totally agree now.
I think if you watch the series just to see some cute ships outside of the usual school/university set up, you'll have a great time.
But don't expect a cinematic master piece. I think they tried to write characters with deep stories, but they completely missed the mark. it feels like every character is missing a deeper layer of emotion. Luckily the actors are talented and can cover it up a lot of times.
I think in theory jack and Joker could've been a lot better. The "comedy" really shows it. In theory they had a lot of great jokes, but the way they edited the series made them all land flat.
Even though if now mostly spoken bad about the series I still gave it a 7. This is mostly because of the ships and the chemistry between the actors. Even though a lot of the characters fall kinda flat, they have a good amount of interesting enough characters to keep you interested. Sadly it takes a long time to reach that point. I'd say it only starts to get really interesting at episode 5. Considering every episode is a hour long... that's just too much.

So yeah just watch the first few episodes in 1.5 speed and once you forget to turn on 1.5x, you're already obsessed and wish there are more episodes.