I was hoping to hear from those who have had good and bad experiences with either phones.
Read official reviews on as many sites as you can. Also watch videos of reviews, lots of good info there.
Like I stated, they all have their pros and cons, it depends on which ones you like, they all will fit you needs. How much storage do you need? How important is battery life? Do you have a preference on screen type, etc?
The threads are full of these questions but only you can answer your question. Unfortunately, no matter what device you choose you will have device envy when the Nexus 5 and Note 3 come out, I promise(I will too).
I have had the iPhone 4S, iPhone 5, S3, S4, Note 2, Nexus 4, and now the HTC One(and still also have the iPhone 5). A bright screen in sunlight, great camera, 32GB minimum storage, and my perceived quality for money spent are all important to me.
-4S screen was too small
-iPhone 5, screen is still too small for everyday use(bad eyes) but is perfect otherwise
-S3 screen wasn't bright enough in sunlight, otherwise was great
-S4 16GB storage with only 8GB usable. I know I can use SD card, but I travel a lot without my personal PC, so I can't always download movies and music via PC and side load to SD card, I need to be able to do it via cellular without a PC, but google play will only store it on internal memory bc of copyright laws(understandable but doesn't fit my needs)
-Note 2, almost perfect, loved this phone, size with a case was a little much but by itself it wasn't bad. Was too much in jeans pocket though.
-Nexus 4, amazing hardware, camera was lacking, very lacking. Bad camera is a deal breaker for me.
-HTC One, still have it and love it, camera is good, battery isn't as good as S4 but it is adequate. Feels good in my hand, good storage, will keep this for a while(maybe, like I said above, Nexus 5, Moto X, who knows how long I can hold out)
All things considered, the Nexus 4 is amazing as long as you don't need a great camera.
I put a lot of stock in reviews from Android Central and YouTube, they review lots and tend to be non biased. Good luck with your search