At 90 cadence a 15 cog in the small chain ring is 14 mph. I rarely ride below that speed and don't miss the 16 cog.

If you use the large chain ring with the 15 tooth cog at 90 cadence you would be riding 23.4 mph. The 17 cog would drop your speed to 20.6 mph.

The 11-28 works well for me in the small chain ring most of the time. If I usually used the large chain ring, I would not like the gaps and would want the 16 cog. I also like the speed steps for the small chain ring much better than the large chain ring.

If I am going 20 mph in the little chain ring and the 12 cog, and I shifted to the large chain ring instead of using the 11 cog; I would need to shift the rear to a 15 or 17 cog to increase my speed. I prefer not making that many shifts.

My 2009 Roubaix had a 12-27 cassette and I primarily used the large chain ring until I found the small chain ring was better suited to my usual riding speeds.
I swapped the 12-27 on the 2009 Roubaix for a 11-28 after I started using the small chain ring more often. I much prefer the 11-28 cassette due to the taller gearing available in the small chain ring.