B757 vs A321, not quite a case of apple vs. oranges but oranges vs. tangerines, certainly. B757 has more power, can carry more payload and goes further than A321, but it comes with a price - higher fuel flow. When 757s superior performance are not needed, A321 wins the day by beancounter's jury decision.
can you sideslip an Airbus in cross wind
Yes I can, thank you for asking. But I sideslip it as A320 is to be sideslipped, not in the way that works in Boeing/Douglas/Tu-134 - i.e. don't hold stick against rudder but release it to neutral when your bank is where you want it.