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I haven't used a Canon TS-E 45/2.8 so I can't compare it directly with the equivalent Mamiya lenses, which would be M645 C 35/3.5N, 45/2.8N and 55/2.8N, but I can make a few relevant comments:
(i) Mamiya M645 lenses are generally as good as most high-quality lenses (incl. Canon, Zeiss, Pentax, and Hasselblad) and better than many;
(ii) Mamiya M645 lenses on a Mirex adapter allow more shift and tilt than a Canon TS-E lens (15mm vs 11mm, and 10 deg vs 8 deg), and all of this movement is usable on the Mirex, while the Canon vignettes as it approaches its max. movements;
(iii) the cost of a new Mirex adapter ($450 US) plus a Mamiya 45/2.8N lens ($250 US*) is less than the price of a TS-E 45/2.8 ($880 US*);
(iv) the cost of adding another Mamiya M645 lens is generally about $200 US* for f = 55mm to 210mm, or about $375 US* for 35mm, and the cost of adding another TS-E lens is about $900 US*;
(v) for focal lengths from 35mm to 210mm, there are six "affordable" M645 N lenses (35, 45, 55, 80, 150 and 210mm) and there are two Canon TS-E lenses (45 and 90mm) - the cost of a new Mirex adapter and all of these M645 lenses is about $1650 US*, and the cost for a TS-E 45/2.8 and 90/2.8 is about $1825 US*;
(vi) for a focal length of 24mm, you're probably better off getting a Canon TS-E 24/3.5L, as the Mamiya M645 24/4 is a fisheye that costs more than the Canon TS-E 24/3.5L (there is a new Mamiya AF645 28/4.5 rectilinear lens - it costs about $5,700 US new); and,
(vii) the Mirex adapter tilt and shift axes are fixed with respect to each other (e.g. for tilt with lens up or down, shift has to be side to side), while the Canon TS-E lenses can be reconfigured (on the workbench) to align or offset the tilt and shift axes - if you need this ability, then Canon TS-E is probably a better solution.
* all lens prices based on eBay sales for used lenses in near-Mint [M-] condition; shipping, taxes and fees not included.