Ok, all things considered I've been doing some research and I think the best of both worlds is to get the Smartphone YOU like and get an external, mobile DAC. this company called HiFiMe does sell their latest 9018 Sabre edition in 3 variants, regular usb, micro usb ( android ) and the latest and greatest USB type C for 69$....
Unlike the dragonfly black by Audioquest which uses worse dac and is priced higher.
http://hifimediy.com/DACs/ready-made-dacs/Sabre-9018-Type-C-DAC
Now it's defenitely not the best in terms of looks ( to keep it cheap ) but it's a below 100$ solution that you can use with any phone that sports usb OnTheGo (OTG), qnywindows machine or Mac for that matter. It draws little power but I'd still consider getting a phone with a good to hefty battery capacity.
Sabre 9018Km is the same one that sits in the Meizu Pro 5 that a lot of you praise here. Of course there are other factors involved not just the dac but this thing gets very good reviews wherever I searched and is priced very low for what it offers.
I was seriously considering getting a Meizu Pro 5 or LG V10 or Lenovo Vibe X 3 but all of them have large screens which I really would rather avoid. The 5,2" of Huawei's P9 is the largest I'd be comfortable with in my daily use I think.
I'm still using my good old iPhone 4s bought on launch which is 5 years old now and it's battery is really on it's last legs...
I don't intend to play any games on my phone but being a sucker for that Leica monochrome images for years I think, getting myself a p9 or waiting for p10 and buying that external sabre dac from hifime would be a good choice.
However I also have to invest in new pair of headphones as I'm not too lucky with mine.
My main Fidelio X1 have an audio in broken, lost my klipsch x10i couple of months ago, 2 pairs of klipsch image one sent back to amazon as they broke in the same spot from normal use.
I'm now left with old sennheisers hd418 which I bought to be the "just in case" crappy solution many years ago, I do also have the a jays four iems but they are lifeless to me, no emetion while listening to those cheap'os.
I"m thinking of getting the momentum mk2 over year next.
Anyhoot long post, sorry ^^'