First up, Wet 'n' Wild Behind Closed Doors (from the elusive On the Prowl collection from last fall) versus Spoiled Ants in My Pants. Both have red glitter (small and larger hex) in a sheer black base.
These two look pretty much identical in the bottle. To try them on the nail, I layered them over Wet 'n' Wild Wild Shine Black Creme. Ants in My Pants had a thick base that made it easier to get the big hex glitter out of the bottle compared to Behind Closed Doors. I used only one coat of the Spoiled to two of the Wet 'n' Wild and the Spoiled nails still had a lot more glitter on them. This did make the Spoiled nails more bumpy, but top coat would have fixed that—I didn't use any for these swatches. (Please try not to let my cleanup issues distract you as you ponder the comparison photos.)
Second (and last) up, Wet 'n' Wild Correction Tape versus Spoiled Trust Fund Baby. Correction Tape was also from On the Prowl. These have gold and turquoise hex glitter, bright purple square glitter, and black glitter in a clear base.
I layered these over Sephora by OPI Opening Night, which I see now was a bit too dark to let the black glitter show (evidently I still have some issues with that). In this case, the Wet 'n' Wild and the Spoiled looked virtually identical on the nail (I used two coats of each). You have to look really closely to see that the Wet 'n' Wild's black glitter is square while the Spoiled's is hex.
From a glitter perspective, the Spoiled polishes deliver nicely. From a brush perspective, Spoiled wouldn't be my first choice; the brush is wide and floppy. For dabbing on glitter, it's okay; I'm not sure how it'll be for a creme or shimmer. I did buy one of each of those for comparison purposes, so at some point I'll be able to answer that question.