I got my Galaxy S5 in May and it is now annoyingly slow. Apps take longer to boot up, sometimes when my keyboard comes up I can type but no words show up, sometimes it won't turn on and I have to continually hAve to press the power buttons, sometimes it just freezes up and I hAve to take the battery out. This really pisses me off considering that I haven't even had "the next big thing" for a year. I have not dropped it in any water and my virus app says it's clean. Bout 90% sure I'm never getting a Samsung phone again as I also had these problems with my S3 previously.
Read more: Why is my Galaxy S5 so slow?