Aperture, disappointing RAW conversion

A few days ago, I mentioned that I'll give Aperture 3 a try and see if it will get incorporated into my workflow.  It failed.  First off, it is slow in rendering large sets of photos, I have to wait a few seconds while it rendered the image in Preview.  Second, a slight crop or horizon adjustment very noticeably degraded the sharpness from the original compared to Capture NX2.  Third, another turnoff is when exporting the files into an external editor, it makes a TIFF version of that file.  While it makes sense somewhat to do that, I now have huge TIFF versions to deal with.  Looks like Zack Arias got it working pretty good with Photo Mechanic, Lightroom, and Photoshop (go see his blog), I might give that approach a try.