So here are the contenders ....
From left to right ... Glitter Gal Fuchsia, Chemistry 601, Ozotic 601, Glitter Gal Frappe
Just from the bottles you can see that the 601 polishes look identical. GG Fuchsia is close but there is more of a rainbow and Frappe is a lighter colour all together.
Again left to right ... Glitter Gal Fuchsia, Chemistry 601, Ozotic Pro 601, Glitter Gal Frappe
These are 2 coats of each on the colour wheel and you'll notice that the Glitter Gal Fuchsia and Chemistry 601 are a similar shade of pink but the difference is that the Glitter Gal is a linear holo with that full rainbow appearing while the Chemistry is a scatter. Frappe is definitely a lot closer in colour to the Ozotic in this shot [although again one is linear one is scattered] - they aren't as similar as the Fuchsia and Chemistry though.
Left to right ... Chemistry 601, Ozotic 601, Chemistry 601, Ozotic 601
Pretty close but slightly different - the Ozotic is a lot more sheer than the Chemistry. This is 3 coats of Ozotic and 2 of Chemistry. Plus the Chemistry is noticeably darker and doesn't show the white dots of holo so much when they aren't out blinging in the sun.
** Final Verdict **
All up it's a hard call when you compare scattered and linear holos. I love Chemistry 601 and definitely prefer it over Ozotic 601 just because it is a brighter pink and doesn't have the white spots in the shade. Both the Glitter Gals are pretty nice but I'd definitely pick of Fuchsia just because Frappe is rather sheer.