its just a harness so yeah, most are cheap. If your looking for high quality you could always build one to your liking. I just used silverstars thus far, the upgrade of the harness is worth the money alone. Eventually when I have coin for LED headlights i would love some JW's or trucs, theres no comparison in quality there and you will pay for it. IMO anyother LED- ebay junk isnt worth wasting your money on, nor is it safe blinding fellow drivers with poorly lensed lights.
With that said, I have no experience running LED + harness, but I would suspect if you bought a good LED light, you wont need, or notice a harness.
I would suggest trying the harness first, then If you want more light output you have all options now available. h4....Hid... LED....
on a side note: I added a small light bar to my bumper, months after the harness. The bar added an option of extremely white light + an amber setting. What Ive learned by having the ability to turn on intense white light, and having halogen headlights, is that I dont actually like having intense clear lighting always. Softer light (halogen) makes for a more comfortable driving experience at night. Extreme contrast in lighting and surroundings vs clarity is a rather large and untouched upon topic, which Ive never read about when I was researching lighting upgrades.
hope this gives some food for thought, youll love the upgrade no matter what you choose.