It's surprising that I haven't comented on the film in this thread yet, given the fact that I saw it twice in the cinema. The second time I dragged my best friend with me, eho is also a Jarmusch admirer, and was slightly disappointed - Maybe I had given the film a bit too much praise. 
Imo Dead Man and Stranger than Paradise are by far Jarmusch's best films, but that doesn't mean much imo, as these two are among the best films ever, from any decade or country. Broken Flowers never had a similar power, besides the haunting last 360 degree shot, which was a perfect ending for the too dry and self-conscious Murray. I think the sometimes "plain" delivery by Jarmusch was intentional, as it fitted the character of Murray very well. Deep, but already a bit shallow, as he has been obviously dying the last couple of years. The last scene is for me the moment he wakes up. I find the film more similar to Jarmusch's weaker efforts (Night on Earth, Mystery Train) in its episode style and (too) wry humor. Nevertheless one of the highlights of 2005 for me. 
Don't see a reason to "give up" on Jarmusch, really. It's not like any director can make one flawless masterpiece after the other!