My main reason for getting the Cowon iaudio10 was the battery life (which for my phone wasn't good at all) and obviously good, clear and detailed sound. And since I'd read a lot of positive reviews about Cowon, I decided to test it out, and wasn't disappointed in the least. Now it's my primary music source, and save for the capacitive touch buttons and low screen quality, I'm totally satisfied; extremely good bang for the buck. Normal usage of about 2 hours a day easily takes me 5 full days without the need for charging.
Now that you say you would require a preset with clear or tight bass sound or boost, without distorting the other frequencies, all the Jet Effect EQ presets relating to bass enhancement, plus the Mach3bass and so on do exactly that. Plus, I would definitely suggest trying out EQ customization with a few of your favourite songs so that you get an idea of the level of detail I am talking about.
Finally since you already own the Note 2, if battery isn't a major concern with the phone, I'd suggest you save the cash and invest in good headphones or portable amps (your Shure SE 215 should be good enough I think). FiiO E6 is definitely worth a try. Around 1700 INR online. It should definitely improve your SE 215's overall sound clarity and depth besides the overall volume level, based on my experience with E6.
Btw, the new V Moda Vamp Verza and Metallo case combo looks and feels awesome, but its only made for the Galaxy S3 and iPhone 5 as of now, so maybe you can exchange your Note 2 for an S3! Jokes apart, I do wish we could try out these amps and headphones at some retailer or distributor before buying. There's a shop called Pristine Note (pristinenote.com) in Mumbai where apparently you can test out products before buying. Hope someone starts out one here in Delhi!
Cheers again, and happy listening!