I've had EQ since EQ4 and now have 7. Version 6 can do most of what 7 does except for photo quilts. So if you are not into translating photos into quilts I'd go for 6. The other issue with 6 is that you have a limited number of installs. After that there is no recourse but to purchase a new program, even if the installs are because of hard drive issues. In fact I didn't see much of a difference between 5 and 6. I still use the *cookbooks* for 5 when trying to work out a thorny design problem with 7. The basic premise is still the same.
My personal suggestion would be that if you are entirely new to CAD (computer assisted design) software, try to find a copy of 5 which should be quite affordable by now and work with it for a while. And pick up the various manuals. They are easier to use than the online help. There is a learning curve and people seem to either love or hate it.