Tilt shift lenses are something people either love or hate, a matter of personal preference with almost no gray area between the two extremes. If you're here reading this, I'm going to assume you're in the 'love' category, and from here on out I'm going to write as if that assumption is true.
Some background (skip this if you're in a rush):
Back when I shot Canon cameras, I got along just fine freelensing because the aperture didn't close on Canon's lenses when they're detached like Nikon's do. This way, if I wanted a tilt-shift like effect, I could detach the lens for a couple photos, and then quickly resume using my lens the proper way when I was done, instead of having to carry around more stuff and actually swap lenses entirely. My favorite lens to do with this was the 35mm 1.4, because it was wider and my personal preference in tilt shift photos is a wider field of view accented by the crazy bokeh patterns you can create with a tilt shift. Eventually, out of curiosity about what a real tilt shift could do, I bought Canon's 45mm 2.8 TS-E which was an amazing little lens. So naturally, when I moved over to Nikon equipment, I wanted to have a lens like that in my kit. So enter the Nikon 45mm 2.8G PC-E Micro.
The first thing to notice about the Nikon 45mm tilt shift is that it is extremely well built, with high end fit and finish compared to the Canon version of this lens. That is because the Nikon is a professional grade G series lens that costs around $2,000 so it should be! While the Canon is a 1991 design that was not an L series lens.
However, despite that, the Nikon version has a manual aperture ring, while on the [much] cheaper Canon you could change aperture from your camera. Not a huge deal, but I definitely preferred aperture control via camera.
When it comes to reviewing a lens, I see a lot of talk about sharpness and smoothness of bokeh, but not about character. There are people who will prefer a sterile looking lens that's extremely sharp but has nothing interesting looking about the blur it produces, and then there are people who would take a less sharp lens that had a more unique, signature look to it; I fit into this group.
The overall color and contrast for straight out of camera images taken with the 45mm PC-E matched the rest of the professional G lineup being very good, but the part that I actually didn't like was that the bokeh was too smooth. Specular highlights are so smooth that there's very little shimmer effect to them, which makes the out of focus areas less noticeable. To me it almost looks like someone just used the blur tool in photoshop as opposed to the more artistic rendering of the Canon 45mm TS-E.
For me, using a tilt shift for asymmetrical bokeh effects was all about making an image more interesting- and when the blur was too smooth, it lost a little character that made those portions stand out. Of course, there are SO many other ways to use a tilt shift (you know, the proper way), but most wedding photographers are using them for creative focus. For those who actually intend on using this lens for perspective correction and increasing depth of field, this lens is optically superior and will not disappoint as it is one of the sharpest lenses I've ever used.
The images above were taken with the Nikon, and the following image was taken with the Canon 45mm 2.8 TS-E for comparison (look at the more pronounced specular highlights that give a glittery look).
One thing that was very neat about the Nikon 45mm PC-E is that it is also a macro, which was not the case for the Canon version. This made it very useful to have for wedding ring photos and other detail shots, and it was VERY sharp. However, most macro photos, including ring shots, still look better using a longer focal length like 90-100mm.
If you shoot Nikon, and are looking for a tilt shift lens for a wedding, you are obviously going to have to use this or one of the other Nikon versions. I would recommend this lens to those who want to incorporate it into their portraiture and benefit from its macro abilities. And of course, to those who are using tilt shifts for their intended purpose of perspective correction and depth of field enhancement, as opposed to selective focus like most wedding photographers do.
While it is a matter of preference, for those shooting weddings I would actually recommend a wider model, the 24mm 3.5 PC-E, as 45mm is a bit limiting, and a wider model would be better for use in making wide, boring scenes look more interesting for a few shots. I ultimately sold the 45mm off due to lack of use, mainly because the focal length made it difficult to achieve the types of photos I wanted from it.