My opinion is between Damasko and Sinn and disregarding design, Damasko wins by a mile.
It's an overall tougher watch.
I remembered posting in LYN the calculation if you're buying frm Damasko direct... be ready for the shipping charges of 125eur... yes, that is not a typo error... its 125 euros!!
I would rather buy frm g****n...
PM me if you would like to know...
You can chk out this link for some poison.... mine... hehehe
http://www.malaysiawatchforum.com/index.php/topic,2606.0.html 
Oh yeah, which Damasko and which Sinn are you interested in?
Might give ppl here some idea of comparisons...