For me a lot depends on what you use a PC for. If you use a lot of Microsoft applications a case can be made to look at another windows based PC and a Windows based smart phone. If your main usage is surfing the web, calendar functions, music, pictures, and the like it matters less what the operating system is.
I personally have been very pleased with my iPhone(s) in the area of ease of setup, use, reliability, available "apps" and integration with my PC. I'm looking at getting an IPad for Christmas (many hints have been issued)which will relegate my Windows laptop to the occasional Excel spreadsheet device. Then things I update on the IPhone such as contacts, mail, pictures, calendar will also show up on the IPad (assuming both have access to the internet)
I have AT&T and as long as I'm near major highways, cities, towns it seems to work OK. Many state parks I visit, AT&T is nowhere to be found but I see folks using their Verizon phones.
Currently when away from home I use the IPhone for everything, have found no need for a laptop on the road. Sometimes I'd like a bigger screen but can deal with it.