If your option is 1080i (60 samples per second) versus 24P, then more per second is better if you have fast action. This probably allows you to reduce motion blur (play with shutter) as well.
However Twixtor in Avid implies a bit of fooling around if your source media is not at the frame rate of your final render.
Example going to a 24P project:
1-open a 60i (30 FPS interlaced) project in Avid. import the native 60i footage into this project.
2-apply the Twixtor plugin. Set the speed reduction to 24/30=.8 and render. mixdown or transcode the video to a new sequence.
3-close the 60i project and open a new 24p project. within this 24p project, open the bin from the 60i project described in step 2
4-drag the mixed down sequence from step 2 into the timeline. avid will ask you if you want to reset the framerate to the project framerate(which is 23.976). Answer yes
5-the Sequence on the timeline is now 23.976fps which can be exported to a master