I don't own the HeadRoom amp+dac combo, only the UE10, so I won't give a definite vote on your poll because it would be unfair considering I haven't heard the former.
Well, yes the UE10 are better than the Etys, there's no doubt about it, but I like to relieve you of this "upgrade stress" a bit: At the moment my UE10s are at the UE lab for a refit - and I do miss them, but being without them led me back to my Etys. Now I am kind of rediscovering them. And damn do they sound good, I enjoy a dose of them everyday now *g*.
As it has been said before, upgrading from stock earbuds to your current Etys was probably a bigger step than upgrading to the UE10s from the Etys. Nevertheless you will easily notice the difference, and most probably enjoy it. On the other hand a DAC will probably improve your home and your portable rig, but keep in mind that using the MicroDac on the go will give you a battery lifetime of 8 hours (offical), while irvin59 said it's more like 4 hours in reality.
My inofficial vote would go to the UE10.
Good luck on reasonable money spending *g*
EDIT: Ah I just saw you're talking about Home DAC - so not for portable use. Well, in that case consider my battery lifetime hints obsolete.
Marcus