Has anyone used the Hifiman TWS 600?

I saw the HIFIMAN TWS 600 advertised on Audiogon and decided to order them for $79 on sale from $199.  They sound absolutely awful!. Very narrow, tinny sound.  There is a note in the box that says they need to 10-20 hours to break-in for them to sound their best. I have run them for about 4 hours so far. I can't bear listening to them so have them running off a laptop in my office. 

Has anyone experienced the same?  Does the sound dramatically improve after 10 hours ?
Thank you 

I really like mine, but how is the seal?

I used after market ear tips with expanding foam.

This is a problem with all the IEM's, that the bass simply is non existent without a tight seal. All of them.
Let me know what you find, OP, and if you find something you like better.

I still have a 20 year old Shure IEM's in large part because the ear positioning and seal is just so hard to get right.  I bought mid-range Fiio IEM's recently and getting the fit right is just obnoxious. The TWS600 is a much easier for me.