I didn’t say don’t get it tuned... but I’ve never heard of one being way off from the auto tune either, without knowing your setup and seeing the file I can’t venture a guess. A professional tune will be worth every penny for sure but out of the box I’ve never been disappointed with the Holley systems. And I’ve got a lot of experience with them and other EFI stand alone systems over the last 8 years using various ones. Holley is king now in the market since for most folks the auto tune is great and gets them going, a solid tune makes it shine real nice though giving the performance associated with the name and cost.
The MS Pro efi works well to, Holley has played catch up them but passed them with a better interface and free auto tune included in the purchase where MSPro charges for the full tuning package. The old DSM link for diamond stars is really similar to the MSPro so coming from it helped but the Holley system is just really straight forward and easy to navigate, it it works right out of the box better than the others.