Yea, three occasion, twice with hd800s and one time with ATH DX5000. HA5050 with DX5000 can be end game for vast majority. It has detail, speed, body thanks for HA5050.
This amps power IEM and headphones equally well.
How I wish I bought the second hand unit for 40% off retail, well it's too late now.
Edit: Also look into Denon sx1,pair that with luxman p750, this combo should be in the same price bracket as ha5050, but will outclass it in every way.