After 10 years or so of flying WB & AH with hat views, switching to TrackIR was a bit of a challenge. I had a heckuva time getting the profile set right, with a corresponding loss of SA. I still lose sight sometimes when it's a particularly hairy knife fight, which rarely happened with hat views. But I'll be using TrackIR for the rest of my life. It adds some realism, it gives me the ability to see some angles quickly that we're hard to get to with a hat, and now that the profile is ironed out my SA is better overall.
If anything, it is easier to acquire a target. I can scan the sky in segments much easier. Adding a HOTAS button to center the view makes gunnery no worse (nor better, alas) than before.