Check that those aftermarket 550-Style headlights are actually HID projectors. Most aftermarket projector headlights are Halogen and they sometimes include an HID kit. A real HID Projector will have much better output than a Halogen Projector with an HID Kit (especially compared to the crappy halogen projector that comes in most aftermarket ebay headlights).
Are these the ones you saw:
https://lmr.com/item/LRS-MST10G/10-12-mustang-s550-style-headlight-kit-gloss-black
Considering, it says H1 bulbs, they are Halogen and most-likely the same crappy Halogen Projectors used in most aftermarket ebay headlights. I'd recommend finding a set that uses real HID Projectors or get these and swap out the projectors in them to good HID Projectors.
Your 2010 has the Optional OEM HID Projectors right? Those Halogen 550-Style will be a downgrade in output. The 2013-2014 OEM HID headlights might fit. Probably similar output to what you have now, just look different.
Are these the ones you saw:
https://lmr.com/item/LRS-MST10G/10-12-mustang-s550-style-headlight-kit-gloss-black
Considering, it says H1 bulbs, they are Halogen and most-likely the same crappy Halogen Projectors used in most aftermarket ebay headlights. I'd recommend finding a set that uses real HID Projectors or get these and swap out the projectors in them to good HID Projectors.
Your 2010 has the Optional OEM HID Projectors right? Those Halogen 550-Style will be a downgrade in output. The 2013-2014 OEM HID headlights might fit. Probably similar output to what you have now, just look different.