DIsclaimer, I've never been to the Easterns. I have been to the SEA and WEAI many times. My thoughts are the following.
1. Both will accept nearly any paper onto their schedule.
2. Some papers are really good. Some are terrible. Presenting at a regional conference does not send a strong signal of research quality or potential.
However, I also feel the following are true as well.
1. Presenting at a conference signals an intention to connect with other researchers.
2. If you get in the right sessions, you might get good feedback. You also might get terrible feedback. Find sessions with researchers you want to meet. Be ready to talk to researchers there giving them a 1-5 minute version of your research. Be ready to email people a draft of your paper for feedback. Put yourself out there. Some people will sit down and give you 10-20 of great feedback. Others might be too busy. This does not signal a lack of enthusiasm but rather a lack of time.
3. It can be a safe place to present to an audience other than your home university. FOr me this was relaxing. For others it might be more stressful. Either way its a useful way to practice.
So I'd say go for it. But it shouldn't replace spending a month working on your research. Because that line on your vita won't really matter that much. But the experience of getting ready to present and presenting, and putting yourself out there to try to network is a valuable one and one I encourage my grad students to do. It should just be complementary to your research generally.