I can only share the admiration of mikeSF's great images. I don't do much landscape astrophotography myself, living in a heavily lightpolluted area. But Mike's work inspired me to do a quick and dirty test to see the difference between wideangle photos with and without astrotracer so here goes (with excuses for the light polluted sky - one has to look at the larger versions to really see the stars):
With Astrotracer:
Without Astrotracer:
Images were 25 second exposures at ISO 400 taken with an SMC DA 18-135mm lens at its widest setting and at full aperture, f/3.5. The 18-135 isn't ideal for astrophotograhy due to its lack of a fixed infinity setting but it will do for this demonstration.
Differences are hard to tell with these downsized images. You may click on images to see larger versions, but these are still only 1/4 of the original. Hoever, the 100% non-resized crops below reveal the differences:
The Sky:
In all examples crops to the left are with Astrotracer and crops to the right are without.
Background:
Foreground:
Obviously, stars are much better recorded with Astrotracer than without, but that comes at the expense of blurred objects on the ground. Hmmmm......before I get a decent wide angle lens for Astrophotograhy I'd better take some lessons from mikeSF on his layering technique!