Hi,
there's a photo of my synapsi on the gear subforum:
http://forums.teamestrogen.com/showthread.php?t=25814
It is a Deda elementi integrated bar and it does have a flat top.
Actually all of my bars have a flat top. The other two are a Token bar and a Deda bar. All of them are carbon.
I love the feel of flat top carbon bars - but I have never had any numbness or pain in my hands with the regular round bars either, so I cannot say...
Hope this helps.