I've owned beats (studio and solo hd) and still own portapros.
Here's my rank according to sound quality: portapros > studio > solo hd
Of course I only bought the beats because they were on sale and I wanted to make my own judgement on them.
I've owned quite a few headphones from Senns (hd650) to Denon (d7000) to Beyers (dt770) but the value on the portapros are just unbeatable. They may look like sh*t but they sound good. After going thru a journey I've reduced my headphone collection to a pair of LCD2 from Audeze and the portapros.