I have Verizon and the Note 4, but given the fact you are looking for a smaller phone, I would suggest staying away from this or the IPhone 6 Plus
You are looking for a relatively inexpensive, smaller medium phone, here are my suggestions as I am a serial upgrader and have used a large amount of phones:
Phones I have personally used: (For ATT/VERIZON/TMOBILE)
Galaxy S5: Not on the smaller side, but not huge, great screen, but the build quality IMO is not as good. Like the Galaxy Note 3 it just feel a little cheap. Feature set is excellent if you are a feature junkie. Great Cameras. Fingerprint reader on these phones is terrible, at least it is on my Galaxy Note 4.
Galaxy Mini: Not a huge fan, similar but the screen, CPU, video is not on par with its bigger brother
LG G3: This is a big phone that feels smaller than it is. It has a very narrow form factor, nice screen, though not as vibrant as the Galaxy Series, its Quad HD Display is sharp, and even with the 801 CPU it still is silky smooth on video etc. This was a personal favorite of mine and I was sorry I sold it.
HTC One (M8): If you like a great speakerphone and sound quality, this is the phone for you, screen is also very good. I love the front speaker design, but you suffer a little with a taller phone. I like HTC's user interface best of the three I have mentioned so far. Camera is lacking if take a lot of pictures with your cell phone. HTC has a nice little bonus that if you crack the screen in the first 6 months they will replace for free. (not sure if they are still doing it)
ON VERIZON:
DROID TURBO in Ballistic Nylon: If I were to get a smaller phone screen, this would be my personal choice. (5.2 is not small, but it is definitely smaller than my 5.7 note. I just love the build quality, the looks, screen and solid battery life 3900mAH. I like its warranty:
Droid Turbo Screen Assurance
Droid Turbo just got even tougher. Now, if the chemically strengthened display becomes damaged during the first two years, you can replace it once for free. It’s the extra confidence you need so you can rise to the moment
I have used the Motorla Photon on Sprint and the Droid Razr Maxx on Verizon and those have been 2 of the most trouble free phones I have ever owned. My boss uses the Moto X which is a small screen model and he loves it, though the screen is too small for my taste.
Notes on Carriers:
I worked for Sprint for 4 years as a National Account Manager and used their Cell Service for a long, long time. IMO, their network just is not up to par with the other providers, but as always go to each carriers website and check their network coverage map to see which might be best.
T-Mobile has been solid for me pretty much all over for both voice and data. It was the only carrier I was able to get bandwidth for internet when I was at San Diego Comic Con. Price wise it's one of the best deals out there
AT&T: I just had a huge difficulty with them in my home and never stayed with them because the are by far, the worst customer service I have dealt with from a carrier perspective
VERIZON: Great network, but they are the most expensive carrier in my market. If not for the fact that my job pays for my cell phone, I would have been on another network.
Great Sources to Check Phone Reviews:
www.phonedog.com
www.phonearena.com
www.phonescoop.com - On release news
Last note, when looking at phones, CPUs should be considered secondary unless you are dealing with the lower end of the market, chances are you will never notice a difference between the Snapdragon 801/805 unless you are huge power user, and even then it will be minimal. The newer SnapDragon 810s are coming out, but Samsung will be using it's own Exynos(sp?) CPU.
I think the worst reason to upgrade a phone is for the CPU, because most modern phones are all fast, look for the features you want.
