You can see the difference in the bottle immediately. As usual these pics don't do justice to either of the polishes so do bear that in mind... The original Holographic only showed a tiny bit of holo under the brightest light and usually looked silver in the bottle, but with the new Holo Hero you can see some of the holo in the bottle. It's not on an OPI DS level, but definitely there.
Here's a wheel swatch. The polish on the left is Marks & Spencer 'Rainbow' which I just threw in for my own amusement - it's much less holo than either of the GOSH polishes but beautiful nonetheless. As soon as I put the GOSH Holos on the wheel I could see that the original is stronger, and I got a few nuggles to verify that it wasn't any bias on my part.
I took this pic after two coats (and before clean-up, soz) to show the dragging - Holo Hero dragged a bit less than Holographic I'd say. I didn't use any base or top coat for these swatches. It was difficult to tell if there's any massive differences in the applications of these because of the different ages - the older bottle is much thicker but how thin Holo Hero will be after a few months remains to be seen.
Finally, three coats of both polishes. L-R Holo, Holo Hero, Holo, Holo Hero.
Here's a bit of pic spam - just couldn't stop snapping these.
I was only planning to swatch these but I can't stop staring at them... may have to make this a full mani!
I'm still glad I have the original Holographic for my stash but the fact that there's a holo this great that's available on the high street for a fiver is amazing. I wish my photos did it justice! May well get a few back ups before they all disappear...