My hubby originally bought me EQ as a gift, I think version 5, and he has upgraded it every time they bring out the latest version. It is not all that difficult to learn the basics, but I find I do not use it as much as I thought I might. I have not designed very many quilts from start to finish in EQ7, but it is great for playing with different layouts of blocks, or different fabric arrangements. It has the ability to scan actual fabrics to go into the fabric libraries, but I have yet to use that feature.
It is fun, and it can be helpful, but I could also get by without it. Designing might take a little longer, but the end result is not going to be any better, imho, for having software. And like Sewnoma said, there are some designs that I simply have not figured out how to draw in EQ7. My avatar quilt is one of them. Several people have asked for the pattern and I am willing to share. I can draw it on graph paper without a problem, but tried to do it in EQ7 and got so frustrated I quit trying. I can't draw it as a block, and I can't draw it as a strip quilt. Maybe someday I'll figure it out!