I'm flipping back and forth between the two since I haven't decided which one I like better.
For serve return I can hit the 2 offensively much more often than the 1. I get better angles with the one hander. I get more spin with the 2. I can disguise the 1 better.
My team mates tell me to keep the one because it seems that I hit it correctly and looks very fluid, but I have only been playing about 8 months so I'm probably pretty flexible in terms of which direction to commit to.