iSedora is compilation of open source components, as almost every other DLNA servers out there (Playback, PS3 Media Server etc.). All tied in Java application which doesn't mean it is somewhat limited or slow. It works pretty snappy, in my opinion better than MediaLink, which I used with my PS3 since years, and better than Playback, which I bought recently in great hope it will push ALL my media to my shiny new Sony BluRay player (as it refuses to work with MediaLink at all).
I do not understand why Yazsoft developers doesn't want to implement transcoding in their Playback as it works BRILLIANTLY in iSedora. Thanks to embedded VLC, you can precisely choose which formats has to be transcoded, so you can enjoy hassle free viewing with your device. What's more, this way it is possible to choose between multiple audio and SUBTITLE streams on any device! All works excellent on my set (MacBook Pro and Sony BDP-S370 over "n" WiFi) for streams up to 720p. 1080 streams needs to be pumped by wired Ethernet.
I experienced some troubles with playing some AAC encoded audio files, but I am pretty sure it is because of DRM.
The biggest drawback of iSedora is its PRICE. Developer offers multiple license types, and the lowest one costs $25, which gives you right to stream to ONE device and get updates for 6 MONTHS only! If you want to download new releases for a whole year expect to pay $49! If you want to stream to more than one device, you have to contact developer for a price (all we know is you will get 3 years support then).
Just to compare: MediaLink license with unlimited updates costs $20, when triple license pack of Playback is priced at $15...