I received both for birthday gift. I asked for the e30s after reading on here about them. But wife researched S5i and purchased them. The s5i will work in my shuffle without the need for the belkin adapter I have to use.But apart from that any other things worth considering before I return one. I don’t want to remove from packaging so unable to sound test.

Just spotted this thread:

But apart from that any other things worth considering before I return one. I don’t want to remove from packaging so unable to sound test.

Unfortunately, what you’re asking is entirely subjective, it’s impossible to describe how ‘phones sound in a way that would really help. I’ve got a pair of Klipsch ‘phones, I think they’re the s5i’s, anyway, they were a replacement for a pair of UE SuperFi 5’s that broke. Great reviews, they seem to be highly regarded; I really dislike them! Midrange is lacking detail, and sounds muffled, so that vocals are ill-defined, and top-end has no real ‘sparkle’. No amount of fiddling with EQ settings made them wearable, for me. I’ve got Mee Electronics M6 Sports, that cost me $24, that knock spots off the Klipsch, and I also wear Shure SE215’s and UE SuperFi 3 Pro and TripleFi 10 Studios, all of which sound great to my ears, so the Klipsch are the odd ones out, for me.
But, lots of reviews like ’em: my point is, after all that, I dislike them, others don’t, a review can only give you clues, it can’t tell you what they’re going to sound like when you wear them, I’m afraid.
I wish I could be more help, but my personal experience can’t let me recommend the Klipsch, others may give entirely opposite advice.
Hope this is of some use, ok?