I have used hardi lap siding and was pleased. Also used the 1x trim and that worked well also. Several years later it seems to be holding paint well, was easy enough to work with etc.
On another building site I frequent, it sound like lots of guys that side for a living that use hardi, do not use their trim. More likely to use wood or Azek. Have not gotten a good handle on why, but it seemed to be a trend.
I used the cedarmill variety,and looking back I would use the smooth if I had it to do over. I think the smooth looks more like wood siding, unless you are going for a more rustic look.