Tilt Shift lens are an excellent addition to the camera bag, IMO.
I use a 24mm TS-E lens extensivley for Landscape work, and am currently contemplating either the 45mm or the 90mm (as I find the 24 often too wide). Primary use is to do Stitching with a flat stitch, as well as adjusting the 'view' (using falling front), and then doing a standard rotated Panorma.
Recently I borrowed a 1ds-III, and found the live view made TS work SO much, it was scary.
I find any CA can be taken out in Camera Raw, before I stitch the shots.
Here is an image I shot recently, (of a fairly famous building!) using a 24mm TS-E, and 3 shots, Left/Center/Right, to obtain a rectilinear stitch. The location dictated I had to be very close. (In fact I was standing as far back as I could, hard up against another building. Due to the number of lines, crisscrossing all over the Pyramid, I think a rotating Pano-stitch would of had a VERY hard time producing this Image.
Canon 5D, 24mm TS-E, f8.0, 15s, Tripod.
3 Shots, Left, center, right, Processed in Camera Raw, stitched in PS CS-3, rectalinear.