Well, I think it could, particularly if you used it with a grill block. It sounds like you should be able to let your temperature go a little higher, before the fan come's on, but it would be something you'd have to monitor pretty closely, initially, to make sure you set it up properly.
I think their is a thread about 1-2 months back which talks about a similar device, but the device operates off of the temperature sensor on the block of the engine, instead of off of the radiator. I'd take a look at that, instead, largely because it's the engine temperature which is an issue, not the radiator temperature. I've had several circumstances where a thermostat wouldn't open and the engine would get hot, long before the radiator, because the thermostat wasn't allowing the cooleant to flow correctly.