I quite like the cardi, especially the white edging. It makes you think of a classic Chanel jacket: clear form, contrast colour, no frills :)

But I agree that your chosen material make a difference and that get's bigger the thicker the yarn is. If you want a tight fabric that often gets very stiff, if you work more loosely the project tends to loose its form. And especially acrylics might deceive you: yarn from a skein that's soft to the touch can work out to be stiff and scratchy when it's crocheted or knitted ;)