I've used both the ASI224MC and (more recently) the ASI290MM to guide my Esprit using a small WO scope piggybacked.
Both of those are really sensitive, not appreciably better guiding between the two, but the 290 picks up globs, galaxy cores, nebulae in 2 second guide subs...
Incidentally, you might want to resolve your so-called rubbish polar alignment
use the polar alignment feature in Sharpcap if you have view of the SCP, works like a charm.