I was headed down Race Logic path up until the point they stopped manufacturing. Plan B was the Holly Dominator ECU with Holly/Davis traction control. However, after I did a little research I discovered that their approach is to compare crankshaft acceleration to a configured threshold. From their site:
"Basically, this Patented system looks for spikes in RPM that are caused by wheel slip. If these spikes are large enough, then a correction is made, reducing the slip."
So it's an open system and it doesn't have a clue what any of the wheels are actually doing. In the end it's the wheels that matter. Modern ECUs have a lot of processing power and software guys are extremely good at algorithms (yeah, I'm a software guy). Since we're talking about a RWD SLC the front wheels provide very good road speed and the rears provide drive speed. So Davis system looks at RPM whereas all of the others that I'm aware of look at all four wheel speeds (and perhaps RPM).
Traction control sits somewhere between improving your lap times to saving your bacon. RPM provides a good idea of what the wheels might actually be doing and Davis Technologies has obviously been very successful with drag racing and truck pulls. However, when it's my bacon in the seat I want those decisions made by a closed system with all of the relevant data.
My plan C is a MoTec system. Hopefully plan D is not needed!