Oddly, PHD2 showed nominal numbers but the images would still be smeared. I first started guiding with my ASI1600mm using my old ST4 autoguider in the ST80 400mm guider and had similar streaky results on stars till I realized I was guiding 3.8 micron pixel size with approx. 13 x 15 micron ST4 pixels. That's when I purchased an ASI120mm for guiding and all was fine.
Tom
