Just wanted to update my findings here.

i have been guiding with my new asi 120mm-s (usb3) togheter with my asi 1600mm-c imaging cam. It's just a great mix! Drivers is working great, I have no bugs that can bodge a imaging session now, so that's great.

I hav been using SEP Multistar, sometimes binning 2x. Also with my East heavy balancing mod, AND I went for the 2 second exposure as mentioned previous.

This year I was able to guide at the Elephant's trunk nebula when it past the worst place for the scope to balance (the zenith) with good result.
I also had some guiding sessions with both RA RMS and DA RMS < 1 trough-out the session. Not as great as Stephane's first images in this thread (RA and DA RMS < 0.5!), but still very nice At the moment every clear sky night is imaging night, so hope to ceep up the pace!