I went in the opposite direction for one of my road bikes. I seldom go up very long and very steep grades and in rolling hills where I want to maintain my speed on the uphill sections as much as possible I wanted the closer gear spacing of the 14-28 cassette.
Another option is to replace the 28 tooth cog with a 32 cog one and have a granny gear to use to grind your way up long grades. When I was touring my freewheel had a 28 tooth large cog in place of the 24 tooth one for normal local riding without any camping gear on the bike. There was a dramatic difference of having a cog with a few more teeth for the long grades.
Another option is a smaller front chainring on the bike. I don't like doing this as I like to pedal on the downhill sections at times to gain speed and momentum for the next uphill section of road.