Hi Zioxious,
Just a suggestion, I would wait till there was a demo possible especially if you're unsure, personally I find it tricky to buy blind unless I'm willing to risk something's potential worth to me but that's just me.
Otherwise, since the MSR 7 has come down a lot, I would suggest those for good bass response.
Just one thing, driver size doesn't necessarily indicate how good bass reponse is going to be.
Before anything else, source quality is important, followed by how much actual bass is in a song, impedence, frequency response, sensitivity but the most difficult to judge as this tends to be personal & subjective, tuning.
Overall, when all said & done, in this case especially, it comes down to how a headphone is tuned, so I would suggest not judging by driver size alone.
Quality Source Matters.
As a final word, as said, if you're set on this, go ahead, be interested to hear how you go either way but in the end it's your choice.