We have been running custom built PC's with capture cards and software from Digital Rapids as well as Digital Rapids pre-built Touchstreams, but we are growing sick of stability issues resulting in everything from halted streams, frozen software to bluescreens.
I'm now looking for more stable and maybe more dedicated encoder solutions. By dedicated I mean encoders which sole purpose is to encode in contrast to Digital Rapids that is built on the multi purpose Windows-platform.
What kind of inputs do you want? Nothing custom or "dedicated" for me (although I use them for a dedicated purpose), but I've had great stability using Mac Minis and Mac Pros, generally using Blackmagic Intensity input cards/boxes and Wirecast software. I know of other stable systems that use the free Flash Media Live Encoder software in place of Wirecast too, but I haven't personally gotten off the ground with that.
The Macs are the expensive part (particularly the Mac Pros), but in theory all of those components and software are also Windows compatible, so it might be worth a shot on your existing hardware. The Blackmagic Intensity Pro or Shuttle is pretty affordable, and Flash Media Live Encoder is free (and Wirecast has a free demo).