They are essentially the same TV only the Q60R has a slightly improved picture processor and a wider colour gamut due to quantum dot. The wider colour gamut is only slightly wider and only applies when you use HDR.
Neither TV makes the mark to be considered a "True" HDR TV and should be considered for SDR only.
If you are in Europe, Samsung negated to sell their higher end models at larger sizes, so the very best HDR TV you can find is the Sony. The Samsung Q70R is the entry-most HDR model, but makes the cut compared to the Q60R due to the addition of local dimming and 1000 nits peak brightness.