Rough Beasts of Empire is pretty good, although the Sisko storyline established there doesn't pay off until Plagues of Night and Raise the Dawn.
I'm a big Sisko fan, and I loved the daring direction DRG took with him in RBoE, and loved the continuation in PoN/RtD even more!
But I do see how other fans were upset. So yes, I do suggest that you read all three of them, to get the entire picture.
As a die hard Niner I fully admit RBoE was a tough one for me to like. It wasn't until PoN & RtD that I came to my senses.
As for the rest of the 'series' I've been extremely pleased, they've been fun stories. For me at least.