I have a 2010 Allez Steel Double, which is similar to your Allez Double, and find that the place where fitting tires can be challenging is clearance due to the front derailleur clamp. There are some 28s that will fit, such as Gatorskins which tend to run a bit small, but you may be better off sticking with your 23s or just going up to 25s. The Touring Plus tires are really good, but probably overkill for what you are describing. They also have a slightly taller profile than Gatorskins. If you decide to try out the Touring Plus tires, you should get them fitted on the bike at the shop so they can keep them if they don't clear your front derailleur clamp.
While my Allez is not my primary commuter, I do use it from time to time on my longish commute (13.5 miles each way). I run Vittoria Rubino Pro III tires (700x23c), and run the front at a little over 100 pounds and the rear at 120 pounds. The bike is comfortable with these pressures. My route has some rather rough spots, but I've never had a pinch flat due to under-inflation. With my current setup, I have no desire to move up to 28s.
Here is a Bicycle Quarterly article on bike pressures that has a useful table for determining proper tire pressures for your weight:
http://www.bikequarterly.com/images/TireDrop.pdf