Stay in Shinsaibashi or Umeda?

Is it better to stay near shinsaibashi or osaka station if I only intend to take a day trip to Nara/Kobe?

Umeda has direct train connections to both Kobe and Nara. Shinsaibashi requires one additional transfer of trains. So, Umeda would be slightly more convenient transportation wise.

I agree, I personal prefer Shinsaibashi (a lot more to see and do, it's right next to Namba) but for convenience Umeda would be better in this case. And there are heaps of places you can go to in Umeda, theres the Loft store too :)

I will be spending 2 days in Osaka itself and 1 day day trip to Nara. So is there still a big difference in convenience?

For exploring Osaka itself, there is not much of a difference in convenience transportation wise. Shinsaibashi is a little bit more central, but has less lines.

I also like Umeda as a base. Lots of dining and shopping opportunities. And lots of good hotels. It is gradually becoming more attractive. In late April, a new district opens up north of Osaka Station.