I have some experience with the Holley sniper on small block fords. When using the ignition control the ecm becomes very sensitive to RFI. This is extra problematic on fords due to the close proximity to the distributor (which is probably your largest source of RFI in the entire engine compartment). You may find the engine runs rough, cuts out unexpectedly, or stalls when you put the air cleaner on. if this happens try covering the distributor with tin foil, if that solves the problem then you know the distributor is the source of the problem. (you can also do this with any other suspected source of RFI like the alternator). to protect the ecm from RFI you can fabricate a shield that bolts to the front 2 studs on the throttle body to block the ecm from RFI. another option would be to leave the tinfoil on the distributor and cover it with one of those rubber boots from the 90's 5.0 mustangs. I know it seems silly but it works well.
you probably won't have issue if you disable the ignition control, but that is probably the best part of running fuel injection. the ignition control will allow you to really dial in your fuel economy, throttle response, and drivability (especially if you use a computer where you can fine tune the mapping - you won't be able to do this on the hand held device). without that you just have an electronic carb.
If you don't have any RFI issues, consider yourself lucky and enjoy. Aside from this issue, Holley makes a great, easy to tune product.