I know this is stupid, but which version of US do you like better?
I like US2 for collisions and graphics and stuff.
But I like the other US for changing orbital properties. See, in US1, You could change the orbital time without the planet/moon being ejected. In US2 if you change eccentricity by like 0.1 the object gets ejected, and I don't like that.
So... which do you like better?