The Elecom is a Bluetooth receiver and is used exactly as you described.
Bluetooth audio quality as of today goes beyond the BT technology alone. Parameters that matter include the design of the receiver (amplification, roll off, harmonic distortion, output impedance etc), IEM power requirement, codec support on both receiver and transmitter (like aptX which was designed to deliver CD quality audio without loss of sound quality). The current myth that Bluetooth audio is inherently crappy is an old perception (that may have been true in the past) that stuck.
ClieOS puts succinctly :
I think the Elecom has a very good analog stage and I cannot perceive a significant difference between wired (LG G2, Sansa Clip, Sony E444) vs Elecom BT(LG G2 aptX). Most importantly, I do not notice coloring to the sound.
I also have a lot of headroom(volume) with all my IEMs including the moderately hard-to-drive Havi. At 200mW into 16 ohms I think it wouldn't be absurd to try a few portable cans as well. I do get hiss with very sensitive IEMs like my Ostry KC06 (Should have included that as a downside).
It has a mic, Fwd/Rev button, play/pause button, Vol+/- rocker, Hold slider, BT pair button, a clip on the back, instant pairing via NFC. All this means I don't have to reach for my phone(even to connect), unless I want to select a particular track, which is not a priority on-the-go. All this for ~50$
Peter has posted a nice review on the
device.
PS: I'll A/B the Havi and Rockets over the weekend and give you a rundown.