I would like to share some comments regarding the Grace as a EM10 owner as well.
Not difficult to drive, I used the Essential phone with a dongle, obviously I also utilized higher DAP’s as well
I am not sure where I read the comment that said they are bass light. The Grace that I have is not bass light. It is not full and deep with loads of sub bass rumble, but in some tracks I hear a nice rumble, not to teeth rattling levels, no. The bass that is present, mid bass, is what provides the fullness. The mid bass is sharp and fast. This is not a DD though. I enjoy the bass in this IEM as it has clarity, because there is no linger in the notes.
In the mids, the tone is excellent in quality, I think the overall tone is great. There is a blending from the mid bass to the mid range that creates fullness, synergy without congestion. At times the sound is warm and at other it displays a neutrality, depending on the genre of music, even with classic rock I have air. This area in the upper mid range seem to create the biggest departure from the EM10. There is overall more air surrounding notes than the EM10, which had a certain congestion through the upper mid, lower treble range. I found no congestion or bottleneck in the mids or upper mids. The sound is open and the notes are distinguishable. The EM10 was not as open sounding as the Grace.
The treble creates a width of stage, overall the stage is more of a rectangle, wider than deep. The is treble is not offensive, never sharp or biting but the tuning is impeccable to create a shimmer which allows the IEM to sound more detailed.