I have tested/used pretty much all the DLNA servers on the market, and by comparison Mezzmo stands out as the most easy-to-configure and broadly compatible DLNA streaming server. The support has been very responsive and updates are released regularly.
It's quite capable at on-the-fly multi-threaded transcoding for those who distribute media simultaneously throughout the residence. Once it handled 4 concurrent transcoding of 3D HD 1080p (30-50GB per video file) over the network without any stutter.
For people with many HD media devices (TVs, gaming consoles, Blu-rays, Ipads) located everywhere, having a centralized DLNA server/transcoder on a fast network backbone (e.g. Wifi-N, Gigabit Ethernet-Over-Power) is hugely important, means massive savings and peace of mind for you, or else you'll have to buy and maintain devices in each room for each TV/Monitor, and have media files scattered in places that you can't remember.
Are we able to get a 50% deal on this gem? I'm happy to write a review on this for those who are not familiar with this software or the DLNA streaming concept in general.