I have both the Pro-tec IPS hip pads, and the Demon Flex-Force Low Padded shorts. I don't like these pads (Pro-tec IPS) because for me they didn't fig snug around the leg/upper thigh region. I ordered a medium and am 6ft 165lbs. They also don't have as thick of padding, and as much tailbone support as the Demon pair does.
As for a review of just the Pro-tec Hip Pads. I give them 3 stars because they aren't the greatest protection, but do have adequate padding all over. The butt, thighs, hip, and quads are all protected which is nice. The padding isn't the thickest but would certainly lessen a blow on a rail or whatever it is that you're using these for.
They're stretchy and conform to your body, and are also pretty light and would easily conceal themselves under a pair of ski/snowboard pants or any type of pant that is somewhat loose.