Just got my Custom Art Harmony 8 (non pros) a couple days ago, at first they felt big but now they feel good with a perfect seal. Need to work on being able to remove them more quickly though.
I will need a couple weeks to get used to it but some initial impressions.
-Details in the mids is amazing
-Isolation is insane (obviously)
-Cord gets tangled super easily
-Lacking the sub bass, a bit hard coming from bass heavy iems (Rha ma750) but I think with time I will get used to it
-Highs are rolled off, which I knew going into this. Not sure if they are too rolled off for my tastes, but I got these for stuff like the Beatles and similar things that did not sound so great on my RHAs
-Mids are less coloured than the 650s, I feel like on the 650s vocals were very often forward, now it seems to really vary between artists/songs.
-Impressed by the soundstage and separation.
-Highs seem more rolled off than the 650s, same with the bass, probably because of the 650s more pronounced mid bass hump. I think my crack + speedball/diff tubes helped improve those areas on my 650s. Currently running these ciems through my MacBook Pro, considering getting something like the fiio e10k but undecided as of now.
So I will need to take some time with these, they can do some amazing things, but for the price they should be good all rounders as well. Time will tell ¯\_(ツ)_/¯