@ShawnHymel yes, that has been my gut feeling all along, as well. I have limited budget so trying to get it right first. The AD2 is back though!
I notice the AD2 is only 30MHz, how often are you needing the extra 20Mhz (or 170Mhz in your case!) in practice? Doesn’t sound like much - though there is of course more to choosing a scope (and a DSO in particular) than just bandwidth - doing some reading on rigol vs siglent and the AD2 limitations