I just ordered the GT100S from Penon Audio, $49 with awesome reviews were very appealing to my eyes.
Now, I must satisfy my ears, I'm not too treble sensitive, but I really dislike sibilances. I own DX80 and Fiio X3II, having noted a previous negative comment regarding the GT100s pairs with the DX80. I got the same issue with the Fiio EX1 (rebranded Titan 1) which can turns out to be rather sibilant on first usage, but after some burn in (8-10hrs) and searching for the right fit with the right tips, the sibilances were gone.
I believe that both tricks will be necessary on the GT100s as well, did anybody else experienced these high peaks so negatively and managed to erase them with burn in?