Has anyone tried all the Linux-based PRV backends?

Hi,

I am in the process of considering a change to a Linux-based server (from Windows) and now need to reconsider which PVR software to use.

I note the options are TVHeadend, VDR, MythTV, DVBLink.

I would be really interested to hear from anyone who tried them all out, what they thought of each and (ultimately), the one they settled on and why.