I did CTP and indoc in March. The guys in my CTP class who chose CRJ are moving much quicker, holding lines in DEN & SLC already. I was senior in my ERJ class and only got a line in LGA this month, in any other base it'll be many months away still.
For movement pick CRJ, for nicer trips with longer legs and perhaps a base closer to you pick ERJ. Don't forget you can always upgrade straight from ERJ to CRJ after 1000hrs so whatever you pick you'll be able to change your mind ~18 months later haha