My Galaxy Nexus went for a swim this past weekend and I was forced to get a phone ASAP instead of waiting a few more weeks (maybe?) for the HTC One to hit Verizon, so I went with the S4.
I don't love it, but I certainly don't hate it either. Course the bloatware had me like

cause I was coming from a pure Android experience, but overall the S4 is a solid phone.
The screen is nice, the multi window feature is a must have, expandable storage, replaceable battery. A lot of pros to this phone.
Samsung stands behind their "cheap plastic" phones, and I would feel more comfortable a year from now have to fix\replace my S4 then I would an HTC One.
All things considered, for me the S4 is a great phone. If Verizon drops the One in the next 10 days, I will consider returning the 4, but that being unlikely I am happy to own the S4.