Hi

I'm not an expert (I'm also a junior artist) but I will speak from what I've been told. Your demo reel should reflect the work position you want to apply to; if your ultimate goal is to get a visual effects artist job, make sure your reel has plenty of cool fx in your reel. The other thing you have to do is to put your very best work in it, not any WIP's or R&D's, just finished shots - I will take out the particle simulation at the end -
Apart from that, your models look great!
Regards