So alot of post recently on Fiio vs Sony A45.
Although it has not been formally addressed by Sony regarding LO and why they don't have it on any DAP's. Again Sony does not have a true DAC implementation like other DAP manufacturers so LO may not have been omitted but simply not possible with Sony's design. But on the other hand Sony's designs do provide for very efficient DAP's and just about the best Battery life ratings of any DAP line. So would you be willing to trade a big chunk of battery life to get Sony to change its design in favor of a proper LO implementation? Personally I wouldn't as I have said already I get great results going HO from my Sony A17 to external amps. My advice, if you can go and demo an A45 and try using via HO to an external amp before making your decision. You can speculate all you want about the A45 and LO vs HO but until you try it via HO you won't know if not having proper LO is that big an issue.
As for bluetooth support and the A45 vs Fiio DAP's. If bluetooth is important then stick with the A45. To date Fiio has had the worst bluetooth implementations and weakest signals of any mainstream DAP's in this price range. If you really want LO and solid bluetooth support then stick with Cayin or Shanling over Fiio. Just check out the Fiio site and see how many firmware updates Fiio's has released for their DAP's, pretty insane if you ask me. It points to a severe lack of quality control for their DAP's on initial release
As for this M7 it looks interesting feature wise but it needs to be a big improvement over the dead on release M3. Basically it looks like a Smartphone without the phone! Fiio's model number choice of M7 seems to indicate low budget like the M3. I mean on paper it has better bluetooth support than even their most expensive DAP's with AptX/AptX-HD and even LDAC support apparently.
This article
https://www.sammobile.com/news/samsungs-exynos-7270-processor-now-powers-a-hifi-music-player/ describes it as a rather unremarkable music player with a Samsung Smartphone processor and chipset crammed into a Chinese DAP. It has a larger and higher resolution screen than the X1-II and X3-III for that matter and pretty much the same as the A45. Specs show 70 mW into 16 ohms and 40 mW into 32 ohms and supports up to a 512 GB microsd card and an FM radio.
I am betting it is Fiio's attempt to compete straight up against the Sony A series right down to the LDAC support and FM radio. Not sure how successful Fiio will be doing that but if it is significantly cheaper than the A45 it may steal some sales from Sony. But if the M7 has as many issues as the M3 and even X1-II had on first release then it may get crushed by the A45 right out of the gate. Should be interesting to see it perform once released and how buggy it is, history is not on Fiio's side!