I had a Sweet unit prior to going with the SPA. It was, by far, the best unit under $100 I could find.
IMO it still is not as nice as the SPA. If you raced Yugos (most hex units) all your life, and jump in an ITE Corvette (sweet) you'll notice a great performance difference...the SPA is a Ferrari F360 Modena Challenge car I was fortunate enough to drive at race speeds a couple of years back.
On one hand the SPA is about twice as expensive as a Sweet, may be hard to justify when a "Corvette" will do. On the other it is only another $100 to go from the Corvette to the F360.
FWIW, I am not one of those "you get what you pay for", "$50 helmet for a $50 head", "I got the best, because I spent the most" type people. Far from it. I like to call myself frugal, others call me a tighta$$. But there are certain concessions that I will not make. This just happens to be one of them.
Mike G, I have an offer for you. I will be looking at another race car on Saturday. If it doesn't have a SPA unit and I buy the car, I'll be in the market for one. If you buy the SPA unit and don't like it, I will buy it from you (never mounted of course) for $200. If you are game...I'll let you know Saturday what the story is.