I see. Should've brought my HP-P1/borrowed another amp to try with the F111. Any recommended portable amp that pairs well with the F111? Also, can you please recommend me alternative tips (preferably foam/tri-flange for the F111, ones that's in the package is not comfy for me :/
I have no idea how the CK100 sounds (shigzeo would know), but I do know that CK100PRO's treble is too HOT for my ears. However, chances are CK100 has bigger-sized soundstage than F111. You should also consider about the F111's availability, brand new unit have been out of stock for a month-ish because FitEar can't keep up with the demands for it.
Mate, you should get a set of Ortofon tips. Amazing. I use them almost exclusively on all my earphones. They are comfortable, have a good internal structure that alleviates pinched sound, and they last well. An excellent amp is the T3 from iBasso and its follow up, the Vorzuge VorzAMPs, ALO Rx, Tralucent T1. Some of these I've reviewed if you want to wade through the too-long text at TouchMyApps. If you care to borrow any, PM me, we might be able to set things up since we live in the same country and クロネコヤマトは簡単.