The new Flex range is superb, I have been using the new 6400M today, stunning bit of kit, really smooth..
the screen is clear and uncluttered, the windows 10 based app is just superb, well written and again really slick..
The latest version of smartSDR is much improved, with the colours leaping off the screen, clear crisp performance just brilliant..
more detail here: Flex from MLS
There’s a book all about SDR “software defined Radio” get it here:
As always have fun! Gaz