Tumblr sux!
I can’t edit a post without loosing all the style coloring and spans - it strips out all markup beyond line breaks to its liking! And forgetting it each time I have to then delete and re-post the messed up entry which lost all mark-up! Therefore it’s the worst blogging service I’ve ever used so far!
And I would be lost without ScribeFire which allows me to post entries marked-up to my liking and even edit them. OK, one good point at Tumblr is presence of MetaWebLog API, which allows doing so. But here again it takes time to make updates available for some reason, so to edit it ScribeFire I have to wait 5-10 min before I can edit!
It’s what you call: looks nice but isn’t flexible enough. Like a lot of new gadgets and operating systems good for kids and elders but too independent for a pro who needs them to do what he wants and not what they want! ;-P