While I think craftymech's TPG is an awesome little piece of engineering, I had to go with the outrun circuit. I only wish John was selling them instead of just giving us the plans (hey crafty or andy, you wanna make and sell them? I'd buy one!). I think that for our particular niche of the already niche market, johns is more useful to us. If this was KLOV's UCA's Id vote for the TPG
As for the howler, heard real bad things about quality of hardware, and more over , I really didnt like wolf's accusations towards Andy/Ultimarc. That and the guy hasn't even been on the forums in like 6 months.
As for the Ultimarc I/O , while think its superior to the howler, I dont run or ever plan to run LEDs on my cab. Love all the other ultimarc stuff though, and Andy is just an awesome guy, in stark contrast to engg , Andy logged in yesterday!