I think the thrust reverser option adds 130 kg,s per side so nearer to .25 tonne heavier which is still significant with only 21 tonnes max all up.We almost always had to carry ballast to get the c of g rearwards.The brakes are excellent if you use them as designed,and i never aquaplaned one in over 2000 hrs.The windshield wiper system is the best ive seen ,why did Boeing put those "moggy minor" ones on 73,s?
I thought (may be wrong) that the ammount of pressure used when you select the emergency brake was proportionate to the ammount you displace the lever.