Going to reply to my original post as a way of responding to all the feedback. Thanks for all the input.
Sorry I didn't specify 2880dpi in my op. The reasons I've been in the habit of printing at 1440 is mainly about the difference in speed, and also based on a memory of reading Michael's opinion expressed on the LL site that a visible difference is hard to see between 1440 and 2880 (hope I'm remembering this correctly and not misrepresenting, I seem to recall this opinion in the review of the 2200?, which I've been printing with up til purchasing the 3880 this month).
The reason behind my original question was noticing on the Epson site that they provide profiles for some papers for both 1440 and 2880, but not in the case of the Exhibition Fiber profile I found. After reading the responses, I may just decide to get in the habit of printing at 2880.
Thanks again to all who responded.