No product is 100% effective, because sometimes the fish are too far gone before treatment even starts. There can be spots inside the gills that you can't even see, so it CAN be worse than it looks.
That said, both products work, under the right circumstances. Ich Attack is safe for your plants and inverts, Super Ick Cure is NOT. Also, some pretty obnoxious side effects (staining, etc.) with Super Ick Cure. Personally, in all but really bad cases, I personally would go with Ich Attack (which, again, has been used successfully by many). In the worst cases, Quick Cure is a solid choice, but again, the staining, high copper content and negative effect on plants and inverts means it's a pretty drastic choice. Super Ick Cure, from what I've been able to determine, has about the worst track record of the bunch. It's not as safe to use as Ich Attack, and it's not as effective as Quick Cure. So why bother with it?
Frankly, if I didn't have plants and inverts, I'd simply go with the heat + salt method, which has been proven effective time and time again. It's not fast, but 100% natural and it works.