I have two of them. One carbureted, and one EFI. I would have to say, I like the carbureted one better. The EFI version has given me fits in the past. Once I got it dialed in, it's given me great service. The biggest expense on the carbureted version was the governor. Replacing it was over $1000. But, that's about it! It's reliable, and bullet proof!
The EFI is difficult to do field repairs when a sensor, wire, throttle body, or ECU goes south. Basically, I have to take it in for most repairs. That alone can be a hassle, and expensive. I'm glad I have it, but I've had to swallow a lot of Tylenol at times repairing it!
I do have a colleague who has an EFI, and hasn't had near the problems I've had with mine.