Summary: This is the ideal product photography lens for small to medium sized objects on a full-frame camera. I guess I don't REALLY need the precision focusing abilities that this lens provides for posting product shots on the online auction site (you know the one), but I find that the quality of the image makes a big impression and brings in higher sales if it looks professional--plus I just enjoy playing with what this lens can do.
Conclusion: I actually borrowed this lens from Canon a year ago for testing and just happened to have a small assignment shooting a large antique tractor truck for a calendar while I had the lens. I was absolutely blown away by the image quality then and knew that I would have to own this lens at some point. And while I'm still shooting architecture most of the time, I don't anticipate using it much for that except for the possible detail shot of wrought iron, woodwork, etc.
Pros: Superior build quality, Super-sharp images, easy to use, useful for macro photography, light weight & relatively small
Summary: An absolutely awesome lens. Definitely worth the buy. Great for portraits, macro, architecture, flowers, etc... But don't take my word for it. Read the reviews online. Lots of good things being said about this lens. This is a great lens.
Summary: If Canon were to make a macro version of this lens, they could easily charge $3,000 for it. When I view my Canon 5D Mark II files at 100% the clarity and definition is spectacular. I've shot just about every Canon lens. This one is the best optically. The only hitch is some CA wide-open.
Summary: Here's a few pics I've taken with it: http://automotomedia.net/showthread.php/82-Canon-90mm-TS-E-fun-for-taking-shots-of-cars-motorcycles! Rented a 45 and didn't like the image quality. This lense was considerably better and tack sharp when not tilted/shifted.
Summary: If you look for a tacky sharp short tele-lens with total depth of field control, the Canon 90mm f2.8 T/S is the ultimate answer. With this lens you can transit easily from landscapes to portraits to macro shoots. Adding a 12 or 16mm extension tube you go thru 1:1 macros with an amazing depth of field.
Summary: This lens is great for shooting product photography. I use it for food, shoes, bags, jewelry, and a lot of things. Sometimes, I add two macro rings and get fairly high magnification (like 1:1 or half life size) but the image quality is still very good, with almost zero chromatic aberration thanks to the true double Gauss design. However, when doing product photography, I want to have independent axes for tilt and shift.
Summary: I have the 24LII, 85LII, 200 2L IS and nothing else. After using the TS-E 90, I figured it has every right to be in the same team as the above lenses. Although it's not an L-series lens, I have also used the new Nikon PC-E 85 2.8D ED Micro-Nikkor and the TS-E 90's build quality feels even slightly better. This is an exceptionally good lens. The sharpness is not short of amazing and what's even more impressive is the bokeh.
Pros: Canon's most underrated lens. Exceptionally good sharpness and bokeh
Cons: Not easy to change shift axis w.r.t. tilt axis
Conclusion: Although manual focus is old school, optically this lens is about as good as it gets. The build quality is on par with a L series lens. This lens has a bit of a learning curve through the additional creativity this lens provides makes it worth the effort. It has been one of the most used lens for product & portrait work.