Skoro mieszkasz w Dublinie to zapewne ogarniasz lepiej angielski ode mnie. Jest pewne opracowanie tematu, zapoznaj się z nim. Ja osobiście nie posiadam doświadczenia w pracy z profesjonalnymi wydrukami zdjęć.

Photoshop CS6 - Color Management

A jak nie masz czasu i chęci to chociaż z dwoma fragmentami.

Section 3 - Photoshop CS6 Color Settings -> Conversion Options

Intent: this pop-up menu allows the user to select from four different rendering intents, namely Perceptual, Saturation, Relative Colorimetric and Absolute Colorimetric. Typically, most users will choose between either Relative Colorimetric or Perceptual. A short description on each is provided in the Description section of the Color Settings dialog. A more comprehensive explanation can be found in the Photoshop on-line help files.

With Relative Colorimetric it is only those source colors that are out of gamut (i.e. can't be viewed/printed accurately within the destination color space) that will be mapped to the closest in-gamut color, the remainder are left unchanged. This means that in the case of documents containing lots of out-of-gamut colors the visual relationship between the colors (after conversion) will almost certainly change. With Perceptual, all colors of the source color space will be mapped to the nearest in-gamut color of the destination color space thus maintaining the visual relationship between colours. In other words, with Perceptual the whole document color gamut will be compressed so that it fits within the new color space. The Photoshop default is Relative Colorimetric.
Section 4 - Soft Proofing -> Rendering Intent

Rendering Intent is the setting that appears to cause most confusion and it's generally worth trying both Relative Colorimetric and Perceptual. Typically, Relative Colorimetric will be best but some highly saturated documents will benefit from choosing Perceptual.
Więc Twoje "Przy wybraniu PERCEPTUAL wszystko jest tak jak być powinno." jest moim zdaniem jak najbardziej słusznym stwierdzeniem.