Funny, I always thought Boxleitner was a better fit for JMS style of writing, as his dialogue can be very pulpy and old skool.... and yet, there are moments, especially with G'Kar and Londo, where the words of JMS are sheer poetry.
It was certainly the best role of Boxlietner's career and I thought he brought the perfect energy for the role of galactic hero.
But you really got to give kudos to JMS, as the odds were against him almost the entire 5 season run -- a very limited budget, unexpected departure of key actors, the collapse of the syndicated market -- and yet, he still managed to tell his story from beginning to end, albeit with some alterations along the way.
It is truly a hallmark of great epic sic-fi storytelling.