I haven't tried the MDR-ED12, but I did own its predecessor, the MDR-ED238. The so-called "bass excite tip" does indeed go into the opening of the canal, and while it does increase upper bass response, the resulting sound is just muddy and lacks definition. Maybe the ED12 is better, but based on experience of the previous model, I doubt it'll be better than the EarPods.
Built-in mics on earbuds are surprisingly hard to come by. I know that AKG has the K318, but I haven't heard it. There's also the Skullcandy Fix Bud (yes, I know...), which is surprisingly good (though lighter on bass), especially if you can grab one for under $20.