Thats actually what I had settled on using, and I think its a fine tool. But even umlet doesn't make writing and viewing large UML diagrams...pleasurable? In the sense that we have tools like vim, word, excel, and chrome that are very polished and allow you to get to work quickly and accurately. Even with umlet, i find myself worrying about the interface too much.
I suspect its more of a problem with the fundamental design of UML though. I think if there was like, a UML-lite spec or something. To me, i feel like UML is to what I want to use as XML is to JSON (or csv for that matter), if that makes any sense.
