Overall I'm happy with this purchase. It sounds great with my old Klipsch KG 2.5. I took a star off due to the headphone amplifier. I tested the headphone amplifier w/ my BT 880 Pro 250 Ohm and AKG M220 Pro. I am not an audiophile but the sound was underwhelming. I would recommend this product for a speaker amp, but get a separate amplifier for your headphones.
Update:
After the date of purchase Mar 31, 2019, optical port broke. Luckily I can still use the use the AUX in from my FX-Audio DAC-X6. I think it broke when I was rearranging my desktop setup. I had to unplug/plug the optical cable a few times. I removed another star due to this durability issue.
veermaharajMake sure your phone supports the APT-X codec so it can deliver the audio at higher resolution.
You can check here which codec(s) your phone supports: https://www.bluetoothcheck.com/
Try with a phone which supports APT-X . Maybe a friend's phone. You will notice the difference.