Problem with the heat strips is that there is no thermostat control. You get cold, you turn it on. It gets too warm, you turn it off.
There is one other issue with the heat pump. If that defrost cycle isn't long enough, the unit freezes up. I had that happen in Branson one October. It rained all day, temps were in the upper 30's. With the outside humidity extremely high the cold outside coils condensed ice on them. The unit did it's defrost cycle but due to the humidity, the ice didn't completely thaw. Well this was going on all day and by the time we got back to the trailer that evening I found the trailer inside was cold with the heat pump blowing luke warm air. I pointed the flash light on the outside of the trailer and found the outside coils encrusted in a block of ice. The next morning I went out and took this picture. You can see the coils still hadn't defrosted. I still use the heat pump, I just exercise a little restraint when the temps reach 40 and it's extremely humid outside.
'04 Classic 30' S.O.,'03 GMC Savana 2500,'14 Honda CTX 700