lens - What advantages does the Canon EF-S 18-55mm III have over the IS II version?

I was wondering if the Canon EF-S 18-55mm III lens had any advantages above the EF-S 18-55mm IS II, which has image stabilizing. The III seems to be a newer version, but hasn't got stabilizing. Will this be a huge problem? I have seen awesome photos taken with the III, but I've also seen some motion blur on a post where they compared both lenses. I'm a beginning photographer, always using the Canon IXUS 220HS (PowerShot ELPH 300HS in America) which has stabilizing.

The answer in this post suggests that the III has less chromatic aberration, but the block diagrams look exactly the same, except for the stabilizing part.

If this lens isn't any better than the IS II version, why would Canon want to replace the IS II with the III in kits?

Does somebody have experience with this lens?

Answer

Here's the basic sequence of Canon's 18-55mm kit lenses from the list at the Canon Camera Museum.

2004/09 EF-S 18-55mm f/3.5-5.6
2004/09 EF-S 18-55mm f/3.5-5.6 USM Optics the same, but with micro-USM focus motor (Sold only in a few initial kits with the 300D).

2005/03 EF-S 18-55mm f/3.5-5.6 II Optically identical to the original. Cosmetic differences only.
2005/03 EF-S 18-55mm f/3.5-5.6 II USM. Optically identical to the original, but with II cosmetic changes and micro-USM focus motor.

2007/09 EF-S 18-55mm f/3.5-5.6 IS New optical design, addition of IS as well as cosmetic changes.

2011/03 EF-S 18-55mm f/3.5-5.6 III Same optics as 2007 IS, but without IS. Cosmetic changes. (not many were produced)
2011/03 EF-S 18-55mm f/3.5-5.6 IS II Same optics as 2007 IS, new IS control algorithm, cosmetic changes.

2013/04 EF-S 18-55mm f/3.5-5.6 IS STM New optical design and Stepping Focus Motor.

Following the initial introduction of both the III and IS II with the 1000D and 600D in March of 2011, the 1000D kits with the III were priced less than those with the IS II. Canon quickly dropped the III from the lineup, at least in the U.S., as consumers overwhelmingly preferred the IS version for a slightly higher cost. Any differences in tested optical performance should be attributable to copy-to-copy variation, as both held the same optical elements as the 2007 EF-S 18-55mm f/3.5-5.6 IS. The 'III' had the element used in the IS unit statically mounted in the optical path, the 'IS II' had an improved IS algorithm in the lens' firmware. Both also had some cosmetic changes that made the rubber zoom rings more closely resemble some of Canon's higher quality offerings.