Well, they say the difference is that Vitagel and Remedy sit on top of the nailplate while IBX penetrates the nail plate and fuses together the top layers of the nail, becoming a permanent part of the nail.
From my experience with Vitagel and IBX, I'd agree that IBX does seem to penetrate the nail; once you've finished applying it, your nail looks naked but healthy. Vitagel was difficult to apply thin enough not to cause problems with peeling; no such problems with IBX, in fact, it seems to enhance wear time. Both IBX and Vitagel seem to ease removal. So far, IBX seems to allow my nails to grow without breaking; I did not notice that with Vitagel. But IBX adds a significant amount of time to your manicure - application, heat, blot, cure - twice on the first application. And that's without using IBX Repair which adds another two cycles. Vitagel is like just another layer of polish - apply and cure. HTH