Are flagships worth the money? That's always been the question. And today, there isn't as much of a difference between a $350 and a $700 smartphone as technology has greatly improved, in addition, the competition is much stiffer. Say in 2012, a $350 phone would give you a pretty sub-par experience. Today, a $350 phone gives close to the experience of a $700 phone. But make no mistakes, corners were cut on the $350 phone. I don't see any $350 phone that gives you the premium experience the aspects:
-Performance
-Battery Life
-Camera in ALL situations, ease of use, ease of activation, time to shot, etc.
-Build Quality
-Ease of usage/how it holds in the hand
-Display (Accuracy and maximum brightness)
-Software refinement
-Fast charging
-Fast Wireless charging
-Fingerprint scanner
-Added features (S-Pen, Stereo speakers, active display, etc)
-Design aspects (location of power button, volume button, fingerprint scanner, ports, etc)
Even a premium phone like the Note 5 doesn't have stereo speakers or an active display. But I think that the Note 5 comes as close as possible to all the criteria above for me. Of course, it depends on your needs and requirements, you can rate certain criteria much higher. ALso, for reference, for 2015 devices, I have used the S6 Edge, S6 Edge Plus, Moto E 2nd gen, Note 5, LG G4 (Both international h815 and Verizon), Droid Turbo 2, Zenfone 2 64/4, and iPhone 6S Plus. And personally, I can say that the Note line is the best for me. Even using other devices, I always went back to my Note 4, and subsequently my Note 5.
With that said, I am also quite impressed with the Verizon Moto E 2nd Gen, which will be $10 next week at Best Buy (no contract pricing). This is quite a steal, imo, and the performance isn't that far off from my Droid Turbo 2, in my usage. Yes, the Turbo 2 is better, BUT certainly not 60x better. Likewise, the MXPE is certainly better, BUT not 40x better. To be fair, the $10 is a Black Friday deal, however, it has dropped to the $20-40 range a number of times. Of course, the Moto E 2nd gen is lacking a number of features, BUT, if you don't care for the added features, then it isn't worth it to pay more. Which comes to my point - yeah the Note 5 costs close to double the MXPE - and for some it is worth the added cost, for others it isn't.
Promotions
Also, as alluded to above, the carrier phones will have more promotions, especially Verizon. I mention Verizon as they sell the vast majority of their high end phones Factory Sim Unlocked. Of course, their Androids do come with quite a bit of bloat - and for some people, they don't mind paying a lot more for no bloat, but if cost is the primary concern, for example, you could have gotten the Note 5 for $233 and the G4 for FREE, after the various promotions running around. Of course, it requires a bit of work to get that pricing. This, compared to the MXPE, or Oneplus X....I don't think that these devices will have a major sale anytime soon.