Welcome, dagata, and thanks for your comments. I may not have been clear about the vignetting, and that word has been misused too, leading to misunderstanding. Vignetting, as opposed to cosine-squared-law falloff, is caused by a physical shading at the extremities of the angle of view. Such as from a too long or too small-diameter lens hood (and all lenses vignette at the limits of their circles of illumination). My used 35 Planar came with the longer hood from the 45 Planar, and there's a UV filter extending it even longer... So that's why I would not have been surprised to see some vignetting, and it's perhaps a little remarkable that there isn't. 🙂
Good to hear your opinion, then, that the 35 is a stupendous lens, if slightly less stupendous than the 45... !