I've had a Bravia 240 mhz TV for 4 years.  It's been excellent.  But Samsung always makes quality televisions.
4k is beautiful, but there's hardly any content whatsoever.  I've run into the same issue with my TV and the refresh rate - so far it's been unnecessary.
Yesterday I saw a 60 inch, 120 mhz, Samsung Smart TV for $700.  That's crazy cheap.  Sure you can nit pick that is has only 2 HDMI ports, etc....but there are crazy deals to be had right now.