EarSonics sm2 v2 or Shure se425?

This is going to be difficult to help without more information about: what you listen, what qualities you expect the most from IEMs (sound signature, isolation, comfort etc etc...)

Hey,

I haven't heard the EarSonics, but I do have the Shure SE425. If you want a balanced sound with absolutely no coloration, then the Shures are a pretty good deal.

If you are looking for something that has its own sound signature, then you might want to go for the EarSonics. From what I see online the EarSonics have a sparkly high end, while the Shure uses a roll off with a slight emphasis on some high frequencies. 

I have had se425 as well, actually just sold them (loved them, but needed the money). The se425 is flat, the two things you are expecting - comfort and isolation, you will get with the shure olives on the se425. Since you like rock and rap, if you want a good quantity of bass, you will not find it with the se425 (a lot of people complain about bass being lacking in the se425, I personally don't care that much for a lot of bass), if you like anything close to a V signature sound, you won't find it with the se425 as well. If you're interested in a flat sound, with great clarity and mid, go for se425.

I have the EarSonics SM3.

They are great IEMs. Very comfortable and crazy good isolation with the foam ear tips.

They are really awesome Rock, Reggae, and Jazz phones. They don't have very much base, very neutral sounding.

Being an EarSonics Owner and not fully falling in love with the IEMs,

I would honestly suggest the Westone line of IEMs