I mean, if you’re using Dreamwidth.org, and the biggest concern is that you can’t duplicate/reblog a post that you like from someone else’s blog on tumblr and make a comment that way vs. saving it as bookmark and commenting via the original source, or even formatting and posting content in a DWORG post versus tumblr’s “post-it-tag-and-go”, “let the followers/tag searcher do all the promoting of content work” that’s kinda the wrong expectation to have.
Not even a huge issue for me, but, I am someone who uses LJ and DW still, so promoting and cross promoting content in communities (where the environment can be controlled). Their format isn’t a bother vs. how it might be for someone 100% unaccustomed to that.
I like the limited format of DW. It allows the user/OP to moderate what or who they want spreading or commenting on their works about and it can’t be duplicated if the user decides to delete the original source outside of the usual thievery levels of Fanpop reposts.
Dreamwidth’s tagging system is also far more manageable and user friendly than tumblr’s imho and you can delete tags with errors in them.
Can’t say much about crossposting, however, outside of doing it manually yourself instead of using the systems in place. That’s bound to look terrible because of the wildly different platforms.