I have both and use both. The im716 is more detailed but less comfortable. The UM1 just barely goes into your ears, more like canal phones. Because of that it doesn't isolate as well either. Unlike the rap on Etys, which I've never heard, the im716 has plenty of bass for me. The UM1 has a little more, but I don't find it boomy. Of course, I listen at low levels, it might sound boomy if you're listening loud. I always where the im716 when I need the most isolation, cutting the grass, working with power tools, etc. For my commute I alternate between the two. I'll wear the im716 for a couple of weeks, until my ear canal starts to get irritated by having something shoved up it for an hour and a half a day. Then I'll switch to the UM1. I ride the DC Metro to work every day. The average background noise on the trains is 95dB. It's not noticeable with the im716. I can hear the background noise with the UM1 and can't listen to quiet music. If you get the im716, get the Shure black foam tips. It takes a little effort to get them on, but they do go on and they're a lot more comfortable than triflanges or the stock foam tips. You can wait on the Shure tips if you buy the UM1, although for me, the stock comply tips don't give me a seal. I needed the large Shure tips. With the im716, I need the medium tips.