Thanks for the encouraging feedback everyone
This new setup certainly is a pleasure to use.
One aspect that I am particularly impressed with is the improvement I'm seeing from dithering between exposures - it seems to have really helped reduce the noise in the final image, especially given i'm using an uncooled DSLR. Bulb exposures on the 400D cannot be triggered via USB, so in the past I had to use a separate battery powered intervalometer that did not support dithering. However as part of this scope upgrade I also sourced a Shoestring DSUSB shutter control, which is compatible with Backyard EOS and PHD guiding. So I can definitely recommend this setup to anyone out there using an older Canon DSLR.
