I've heard a few Soulution based systems several times at audio shows and can't claim to know the sound of the 725 specifically, just a general feel of the brand's "house sound".
From all I've read or heard about, the Robert Kodak Takumi is a very special wonderful sounding preamplifier. My gut feeling pushes me strongly in the direction of the Robert Kodak. I hope that you find the opportunity to hear both.
Charles