^^
I've installed and tuned standalones. They can be a pain in the ass. Installing it is one thing, but getting it working and tuned is another.
Tuning a standalone is no fun. It requires a lot of time and understanding of air, fuel, timing, etc...
My friend still has issues with his Accel DFI (Gen 7+). The motor doesn't start up right away, it takes a few cranks before it'll fire up. It can be fixed, but he hasn't bothered with it.
In the summer and winter, it needs to retuned cos it won't idle right with the temperature being different.
I agree with Charlie, stick with the stock ECU till you exceed the capabilities of it.