I have EQ4 and it works just fine on my up-to-date computer.
It really depends on what you use it for. I use EQ to draw pictures of the quilt that I have designed, to experiment with settings - MOSTLY so I can see the finished measurement of the quilt. For example, I wanted to make a sampler quilt for my guestroom.
I made 12 blocks and knew that wouldn't be enough, so I made 16 and then sat down at the computer and started playing with settings. I wanted my quilt to be about 90" x 90", and I didn't want to make another 8 (or more) blocks. I created the 16 blocks in EQ , in roughly the colors I had used, and then I started "making" quilts of them. Square setting with sashing didn't make them big enough unless I added a lot of borders, but if I set them on point and added sashing, I was getting closer. Then I set them on point with sashings, posts and alternate plain blocks. I was nearly there, so I added a narrow inner border and a 4" outer border. Perfect. Each step of the way, I could see exactly how big the quilt was, so I didn't have to do all the math on paper, and I could see how the sashings and borders looked with each arrangement. I could compare light borders to dark borders and gauge whether or not I needed posts in my sashings. I could make my alternate blocks of the background fabric and then try a darker fabric and then try simple pieced blocks instead of plain blocks.
Those of us who quilted before computers will remember using colored pencils on graph paper and having to do all the math for each possible setting! The patterns I used for my classes and patterns looked pretty un-professional compared to what I can do now, between my CAD and EQ4 programs.
When I am designing quilts for patterns, especially mystery quilts or Block of the Month clubs, I can create a block and save it for use in the finished quilt when I am done, copying and pasting the blocks for each step into the pattern that I will print.
When I am making a quilt for a client, I can quickly draft up a few examples of possible arrangements, save them as jpg images and send them by email (or print them, of course).
So EQ4 works fine for me. I don't need anything else for my personal or professional purposes, and I am not buying stuff I don't need. It's a tool and not a toy for me. I don't sit down to play with it... just for practical purposes. But if you want the upgraded versions, buy it by all means! :)