I have sailed on a sc19 several times... great boat.. very fast.. a little wet.. but who cares!
As mentioned above.. no striker, and the 20 has spreaders (i have even seen double spreaders on them). My friend even flies a spin on his 19 (without spreaders).
the mast is very heavy (and strong) but be VERY gentle on your transums... they are the weak point of that boat and have seen 2 with them ripped out!