I made the decision to go tumblr for a few reasons. I'm going to focus on all of the good things about tumblr first. These are the features I think they have nailed down:

• Ease Of Posting - It's super super simple to post to a tumblr blog. There are a million apps, bookmarklets, iPhone apps, 3rd party services like ping.fm, your email. There's just so many ways to post and that's probably the number one reason I picked tumblr. It's just a really super simple no hassle way of posting to your blog.
• Template Customization - Tumblr has a nice gallery of themes to choose from that will suit pretty much any style, and creating your own theme is very straight forward. I thought this was the perfect amount of customization. Just enough to make it mine, but not so much where I'm defeating the purpose by moving to a more simplified blogging platform.
• Networking - One thing I really like about tumblr is the ability to connect to other tumblr blogs, 'like' posts, follow people, etc. I was looking for a way to find some daily reads and I knew there is a really large user base to choose from. Sometimes I feel like I'm just blogging and the posts are hitting the ceiling and bouncing right back. I'm actually cool with that because I blog partially for my own records anyway. I love looking through the mophoblog and seeing a timeline of the past few years of my life. Anyway, the community aspect of tumblr was appealing to me.
• Security / Reliability - One thing I wanted to remove was the hassle of having to maintain code. I thought this would free up more time to actually blog instead of tinkering with code. Also, I maintain my own server where I have our business and other clients hosted. There is a certain level of responsibility that comes with that. By moving to a hosted solution I don't have to worry about maintaining site and database backups, updating code, staying up on the trends (facebook / google connect, open id, social media reactions, trackbacks, social commenting, etc). I figured this would be a way to totally free me up from any other worries aside from the actual blogging.

Having said that, there were some things I did not like about tumblr. These weren't deal breakers (might be for you, I don't know) but they all sort of added up. I'll list those as well:

• No Filtering - There are a few different "content types" that tumblr allows: Text, Photo, Quote, Link, Chat, Audio & Video. One thing I was sort of baffled by is they did not provide a way to filter the different types of content natively. The read method on the api allows you to filter by type, so why not have that as an option for the templates? Confused on that one. I like to have my content separated by blog entries, photos and mobile photos (or mophoblog as it's called here). I'd have to twist and bend my blog in order to filter and pull content based on those types. Quite possible, sure, but entirely too much work.
• Limited Or No Access To Hi-res Photo - This to me was pretty much the deal breaker. You're allowing me to add content to your system, yet you're not allowing sufficent access to that content should I choose to leave. When you add a photo to tumblr, they create varying sizes of the hi-res version. The original hi-res version is saved, yet you cannot display that image inline, nor can you use a lightbox/thickbox style popup to request the image. That's okay, but you can not access this photo via the API either. That is unacceptable. I'm always leary of that and am glad I ran into this issue early.
• Other Misc API Limitations - Not being able to access the hi-res photo via the API is one issue. But there are also limitations on the number of photos you can add per day via the API. Now, I understand needing to throttle the system to prevent abuse. But how about allowing extra access on a case by case basis, say, when you're trying to import past entries? Tumblr is basically saying, we want to be your blogging platform of choice, but don't plan on doing a mass import of your old blog entries from any other blogging system. I had to add around 80 photos per day, which was their limit. That's cumbersome when you need to add 500+ photos.
• Vague Support - I like Marc LaFountain, I think he's a good guy. But I also suspect (total judgement on my part, I could be wrong) that the communication between him and the development team is sparse. Browse the getsatisfaction tumblr site and you'll see countless replies where he'll basically say "That's not a current feature but I'll pass that along to the development team". Are all of those really being passed to the development team? If they are and if they say no to a particular feature, are the threads being updated? I think not. It's a way to appease the users and it's a bit frustrating, knowing that it's mostly a canned response to a general inquiry. I understand he's in a tight spot because he may not be able to say straight away "no, we can't do that". So I don't know. Here is an example of a thread that was never answered, it was about the hi-res photo not being available through the API. Posted many months ago, never answered. I think it may be a case where they are just sitting on their hands, not sure. Here's another case where the iframe they inject into the site template was causing the page to not validate. It's a really simple fix yet the request is seemingly ignored by either Mark or the development team. Not a huge deal but it doesn't warm my heart.

So there we have it. The thing I missed most, and my ultimate decision for coming back was lack of control. I also feared for my content. If I can't export it from tumblr, and they don't allow a method for me to do that via their API, then my content is locked in.

I do think tumblr brings significant value to the table in a few different areas. It's quick to setup a site. It's easy to post to the site. You can have multiple contributors for group projects. The dashboard and multiple posting methods make it really simple and convenient to use. I'll continue to use tumblr, but only for small one-off projects where setting my own site up would be too much of a pain for what it's worth. See 90daysof.me for an example. Took me very little time to set up and it's easy for me to update.

It took me a short 4 or 5 weeks to realize I wouldn't be able to get some of my content back. Imagine if I kept my tumblr site for a year and posted another 500 photos. And the only way to access those original hi-res photos was to browse to each photo individually, open it up and save it to my local machine. Unacceptable.

So the lesson of the day is: Before using any hosted blogging platform, make sure you know what's going to happen to your content.