I have not put a SD Card in mine yet and the phone still has several gB of room left on it.
I take quite a few pictures, a few every day of things I happen to see that interest me. It is so easy to off load them to the PC that I can't feel the need for the SD card..... but, Best Buy had one of those 12 hour sales and someone on this forum posted about it. I bought a 64 gB and a 32 gB card with free shipping. Almost got the 32 gB card for "free" when you consider what the 64 gB card would have cost plus shipping.
Haven't opened either one of them up, maybe I will, maybe I won't. They won't get lost in the OEM packaging. and one day, at 03:30 in the morning I will get a hair brained idea and want the SD card.
I can't imagine downloading over a 100+ apps. What in the world would you do with that many? I have about 30 technical type apps and that is most likely how it will stay.
I admit to not playing games, no interest there for me at all. I am a retired electronics tech and tired of things that go beep in the night.
Don't get me wrong, I love the S5 because it can handle any thing that I ask it to do. Great little tiny PC it is, write up a document, make a spreadsheet, go surfing for the latest news on the "ISIS" group.... gulp! what a mess that bunch is..... hope it all stays "over there".
but, I cannot feature thinking that the S5 cannot do what you want and you would avoid it because the basic phone "only has 16 gB"...... put in one of those 128 gB cards and the world is your oyster.