Occasional balky media loading. They re built for heavy, continuous use. You can upgrade the Evolution 4 to an Evolution 8, with 400dpi native and 800dpi interpolated resolution.
Resolution is the only difference between the two scanners.
Both scanners are designed for tabletop use, and ANA Tech offers optional stands for both. I wish I could give you lots of good technical reasons why straight-line arrays are better or worse than cameras, but the average user won t notice a lot of difference. The Evolution series uses standard cold-cathode fluorescent lighting. Included with the Evolution 4 and 8 scanners is ANA Tech s large-area dynamic thresholding technology. This is similar to other adaptive thresholding systems, which provide good scans from poor-quality original documents.