Considering Holley sniper EFI for my 1969 340. Thoughts from people who have that set up?

Thanks for all the input guys. I think I'll stick with what I have. All of the add-ons you guys say are necessary is more than I care to deal with/buy.
Thanks again.
I think you are making the right choice. If you're not willing to put the time and money into it it would be an exercise in frustration. Spend the time and effort optimizing what you already have.

Here's a story that seems typical of this scenario. A couple years ago one of my neighbors with a '60s GM product saw the Sniper setup on my Dodge and decided he wanted it too. He admitted to not really knowing much about it and that he was "not a computer guy". I was skeptical of whether he understood what he was getting into but I agreed to to go look over his car and discuss what was needed.

So I'm at his place one night and find the wiring was just a mess - it was all the original 50-odd year old wiring that over the years had been randomly butchered by wayward hands. The OE battery cable was literally hanging on the terminal by one strand of copper - seriously. It was hard to understand how the car even ran or didn't burn to the ground - it was that bad.

I suggested straight out that he should re-wire the whole thing or at least fix all the obvious issues before attempting to install the Sniper. He wasn't saying anything but I could see the the gears turning. I left waiting for him to call me to say forget it or that he was going to need help re-wiring the car but he did neither. What he did do was ignore all my suggestions regarding the wiring and the fuel system and did the install himself without even telling me. Needless to say, it turned into a total clusterf*ck. A few weeks later he called me saying it wouldn't start. No ****.

One night I go over and try to help him figure out what was going on. I asked if he had done this or that and I got blank stares - he barely read the instructions. Neither of us had any idea what he had done and I left without making any progress. Over the next few weeks he tried again and again on his own with no luck. At one point he called me and said he was about to shitcan the whole works and go back to a carb. but I talked him off the ledge. To his credit, he saw it through. It took hours and hours on the phone with Holley tech support though. They eventually helped him get it up and running on the generic tune. He finally seemed OK with it but that was basically the end of it.

Once he had it running, I offered to go over and load the tune from my car since his combo was similar to mine. That never happened but he ended up dropping his SD card off at my house so I could load it for him. After several calls, he never came to pick it up even though he lived right up the road. I didn't hear from him for long time, I figured he was busy or whatever and we weren't close friends. After almost a year I found out from another neighbor he moved. Two years later, I still have the card.

He should have just stayed with the carburetor!