That was me who made that statement.
Personally I'll stick to what I said: DN-1000 with a decent amp (namely) Tralucent T1 wasn't entirely worth the upgrade to DN-2000. Though keep in mind, I have been in the hobby a while now so my intentions to 'upgrade' and actual perception on that wasn't worth it for me.
I just found the DN-2000 a little dry or bland, accompany this with DN-2000's lower level of bass impact made DN-1000 a more fun, involving experience. Plus, I do stand by when you amp DN-1000 you can really extract an extra does of clarity and detail. I believe lin0003 also had a positive experience when amping DN-1000 with an Objective 2.
As for H-300 it has the best bass quality though is very bright earphone, it can be a dream with the right source, the clarity is up there with the best I heard though again, this comes at the price of early fatigue. If however you're a EQ user H-300 can be fine-tuned very much like a race car. You can tweak it's gears and make it cater to your needs.
All 3 can compete quite well actually but DN-1000 wins the freak award offering the best price to performance ratio imo.