I would trust Whiteline's products over any Perrin product hands down. And I have a LOT of Perrin crap on my car.
The noise he's speaking of is from the use of spherical bushings, whereas Whiteline uses a poly bushing. Depending on the tolerances of spherical when they are put together, they can cause issues with noise and it seems as though they had a bad batch since I've never had a problem with mine. Their older model sway bar is horrible. The bushing wear out every year, which causes squeaks, and worse yet, clunking noise in the rear end. Because they use Energy Suspension Bushings, I can only assume they poorly designed the bar or mount to cause unusual stress on the bushings. I have no clue about their updated stuff since I stopped buying from them. I've already gone thru 2 sets of those bushings. The noise from the endlinks were described to be a clunking noise also, but different cause in my case.
If you can't tell, I am very bitter with Perrin products, so keep that in mind when making your decision since I am a bit bias against them.
"We live for a good time, not a long time."
RIP Colin McRae