I just started UNIFI few weeks ago. The D-link DIR 615 router really suckz in term of range. Things got better after change the bandwidth to 20mhz only. The windsurfer made of aluminium doesn't really help in my case. Poor signal in first floor (double storey terrace)

Change the router to TP link WR841ND. The range is marginally better. -80 to -90 (1 or 2 bar) measured from Wifi Analyser (Android) at first floor. Hesitating to improve the range further by limiting the bandwidth to 20mhz or not, coz worrying this may compromise a bit on the speed.