When the image comes back to aperture it will come back as the first image in the project filmstrip, but the strip will show manual sorting if you look at the dropdown list just above the image. Click on date and the image will be placed nest to the original. Then hit either the right or left arrow key and the filmstrip will recenter under the images of interest.
I think the pixellation problem is a memory leak problem of wome sort. I also occassionally find that when I am going through large libraries.
I haven't looked for tiff or tif in the metadat block, but if i filter under image type and select tiff in the check box the tiff images will show up. That is important to me since I don't like the files to be managed and the tiffs come back as managed images. I filter for tiff and relocate them to the folder where I want them.
I hope that helps a bit.
I too have seen this rather weird behavior when using Nik HDR 2 with Aperture. I just starting using Nik HDR2 today after downloading the Nik Collections software. In my case I will take a single image into HDR2, make adjustments and return the image to Aperture. When it gets back, at times it is pixelated. The image also "blanks" out when I use the film-strip on the bottom interface. If I change to "full" the image returns??? Not sure whether this is Apertures problem or Nik's HDR2 software algorythym. I suspect that it is Nik's though because I had no problem using HDR Efex 1 with Aperture and I don't have this problem using any of the other Nik products (and I have them all). I have sent a note to Nik about this earlier today. We'll see what happens.
There is a lengthy thread on this subject at link below:
The last two comments suggest invoking HDR Efex Pro 2 from browser view side-steps the issue to some extent.
Note - Google released a combined install package for the complete collection which I also installed today. It seems to be simply a repackaged installer though, not a bug fix release.
Thanks "Corky02". Tried invoking HDR2 from the Aperture "Browser" window, made adjustments in HDR2 and returned to Aperture with no problem. I can even peruse the image in any of the other viewer choices that I wish to. I agree that it's a kind of weird way to do this, but it works as a work-around. At least Aperture>HDR2>Aperture is workable now and makes HDR2 quite usable. Don't particularly like the order placement of the returned image, but as others have mentioned you can "sort" for workable nesting.
Now, I'm left with just 2 issues with Aperture:
1) Somewhat better Noise Reduction
2) Usable Lens Correction (Although I currently use PT Lens for this)
If I had these 2 items, at least for me, I probably would never look at Adobe Lightroom again (Yeah Right!!).
Maybe Aperture 4 will address this for me. I WISH!