Stick with it. DS9 gets better with age and really takes off in Season 3.
The only actors that were any good in DS9 from the start were Armin Shimmerman (Quark), Rene Auberjonois (Odo), Coin Meeny (Miles Obrien) and Andrew Robinson (Garak).
The quality of acting from the others almost made me quit watching the series.
But it's trek, so I endure. (as we have done many many times over the years WRT to our trek actors)
Avery Brooks was completely misscast. I more than support casting an Afican American for the part, but for gods sake choose one that can act. He's the only actor in trek that each time I watch the series I'm rooting for him to improve on the acting side. Incapable of showing any emotion other than anger. To cast someone as limited as he was with his acting as the centerpiece of the show was a mistake. Lucky for the series and him that DS9 really didn't "center" on the Captain.
Nana Visitor (as stated many times in this thread) just didn't get it. Much like Roxanne overacted playing B'elanna, Nana did the same with Kyra. She improved drastically as the seasons unfolded.
Alexander Siddig, while seemingly being the "heart throb" for the gals watching this series, was off the charts horrible. If it wasn't for his relationship with Garak and later Miles, they could have deleted him.
Terry Farrell was OK, but she really didn't take off until the character drops the "perfect" vale they had over her in the beginning.
When half your main group isn't very good, it makes for some tough watching.
But DS9 is all about the stories and relationships and they also had the benifit of reusing some of the franchises greatest reocurring characters.
ENJOY... and don't jump ship!!