Update on my EFI Cub Cadet
Well - since this started so long ago, I'll recap that I bought a new EFI Cub Cadet in Spring. With about 3 or 4 hours on it the engine blew - totally - and was replaced under warranty.
Ever since I got it back the Cub has been perfect in every way. It runs beautifully hot or cold, it starts up on the 2nd turn with the throttle at any position, there's no surging or any other of the numerous things that drive me nuts with carbureted engines. I'm totally satisfied with my choice of the EFI and would recommend it to anyone. It's not a new / untested system really, it's similar to what they started putting on cars over 30 years ago only adapted for the Cub engine.
I also think that once it got broken in, the replacement engine uses LESS fuel than my old 10hp Wheel Horse was using. It's been stated that the EFI engines save 25% on gasoline use and I can believe it, which just goes to show how inefficient carburetors are and what a poor job they do of metering fuel compared to an intelligent system that keeps constant track of what is going out the exhaust.
Some might say 'but I can fix a carburetor myself'. Yes, you can, and you can bet that you will need to. At least you will try. I've had my fill of tinkering with them, and governors - another diabolical Rube Goldberg contraption.
EFI - highly recommended.