I’ve used Easy Grammar. I have a very old copy that I’ve been using for about 20 years, so I’m sure mine is a bit different than the current version. When I purchased mine, it was one volume. Now I think that EG is sold in a workbook format for each grade level. That’s probably why it isn’t recommended much by CM fans who would advocate holding off on grammar and covering it all in one chunk instead of spreading it out over the elementary years.
I’m going to begin Daily Grams this fall with one of my children who just needs lots of review. That is how I see Daily Grams — a review of what’s already been learned. Since it will be new to us, I can’t answer whether you’d still need EG, but as far as I can tell, DG’s doesn’t do any teaching and wouldn’t be a stand-alone grammar program.