There are so many comparison charts on the web, many with contradictory claims, that it's difficult to get a straight answer, especially when so many of the characteristics of steel are in the heat treat.
But Crucible shows that O1 -- which is very close to 1095 on the toughness scale -- is equal to A2 for toughness. A2 will give you a bit more wear resistance.
Check out Crucible's comparison chart at the bottom of this link (Resistance to chipping is the toughness bar):
http://www.crucible.com/pdfs/SelectorKnifePocketRotatedCrucibleLLC.pdf
My own sense is that you don't get much difference in toughness -- resistance to chipping and breaking -- with 1095 and A2. Both are tough steels. You could drop the carbon down from 1095 a bit and soften the heat treat to get an even tougher steel. Or, if you could stand a little better wear resistance, you could go with a better steel, such as 3v or Vanadis 4 Extra.
But for just the two steels that the OP is asking about, they are so close that he should mostly pay attention to the large effects of heat treat, rather than the small differences between A2 and 1095.