I am sort of a seat-of-my-pants quilter, so I do things however suits the moment. So sometimes I press, sometimes I don't. Sometimes I press part of a quilt and then stop, or start pressing halfway through a quilt. Sometimes my quilts turn out great, sometimes they are loaded with flaws. I'm OK with all of that!
Don't tell the quilt police, but I make entire quilts where I don't press anything, ever. The seam allowances end up where they end up, and nobody is the wiser. It's somewhat more difficult to do stitch-in-the-ditch quilting on it, but if you're a bit wobbly anyway (like I am) it's not going to end up looking much different.
Depends on why you're quilting, I think. If a perfect-as-possible finished quilt is your goal, then pressing is probably the way to go. If you're just putting together something for yourself or close family and doing it to have fun and enjoy the colors...pressing (in my opinion) is optional. Also depends on personality type - some folks really care what the back of the quilt looks like even if nobody will ever see it. Me...I figure if the quilt doesn't fall apart in the wash, it's all good.
