I don't know much about Jamis, but I do know that you are about to throw away alot of money plus taxes.
" The stupid thing is that I mostly need the bike to ride around the paved city tracks with occasional shortcuts to gravel."
Indeed that is fairly ridiculous, you can probably buy any crap bike and do that. Unless you are serious about moutain biking and are planning on hittin trails at least every other day, don't buy such an expensive bike. Buy something midrange, focus on comfort and stability, and looks if that's important. But if you are riding road with occasional gravel, there is no way in heck your components are going to break, especially not your frame. Even if you are planning on getting into mountain biking, buy something mid range, see if you like it, then upgrade your bike or buy something more serious, at this point it seems to me you've listened to alot of hype and think that you need to spend alot to get something good, don't fall into the trap most newbies do, I alomst did. Best of luck with your new aquisition, whatever it may be.
Ciao