If you feel you're ready to upgrade to a road bike the question would be if you got the Specialized - would you regret NOT getting the more "roadie" style bike in the short haul?? Since you seem to like them both what do you see yourself riding a year from now??
As for the neck/shoulder pain: if you liked the Specialized coz it was more upright that tells me you're not used to riding in the more bent-over position of a road bike? in which case there will be some muscle/joint/body adjustment that you'll have to go through.
(personally I would ALways vote for the Treks but that's coz I'm just a Trek-Head! LOL)
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"