Quirky Jo (quirkycooking) may be worth contacting too - she has had both (& meaganejane?)
There should be some info here in other threads. Basically no reverse and not quite as strong. Blades can't be submerged in water or placed in dishwasher (I don't put in dishwasher anyway). Temps on TM31 37-50-60 etc, TM21 40-50-60 etc
Hope that helps.