IMO, there's nothing wrong with 4 year old ultegra/105 setup as long as it's been maintained well. Having said that, as mentioned above, fit is crucial and any good LBS will take the time necessary to ensure as much.

Maybe the LBS's didn't spend a lot of time on fitting because they're not sure of a sale. I'd suggest you ask what sort of process they use to fit customers. The frame is only the starting point. My first LBS had me and my Trek 1000 on a trainer where they could observe as well as measure. Swapping out the stem for length and angle is one option as is changing the saddle itself if necessary as well as its position.

I don't think you can wrong with the 1.2 or the Defy. Both are beautiful machines that are in your price range and are suited to the type of cycling that you describe. Another consideration if this is your 'first' bike in a while is the additional gear that will make your cycling experience more enjoyable. At a minimum, things like good cycling shorts, a jersey, gloves, (maybe clipless pedals), shoes, helmet, a tube repair kit and a floor pump are usually found in most experienced cyclists' possession. As you continue, you may find yourself adding gear as well as tools. We all do.