HP doesn't have anything comparable to an rMBP. Their 15" laptops are either low-end, or x360 convertibles. Also they have tiny batteries (under 60 watt-hours in 15" models).
The XPS15 is the closest rMBP competitor, but even that has a smaller battery, and much worse battery life with high-DPI screen (only moderately worse battery life with 1080p screen).
The closest competitor to the rMBP is the T560. It's more than half a pound heavier with extended battery, has only a 1080p screen, and only a dual-core rather than quad-core processor.
The XPS15 is the closest rMBP competitor, but even that has a smaller battery, and much worse battery life with high-DPI screen (only moderately worse battery life with 1080p screen).
The closest competitor to the rMBP is the T560. It's more than half a pound heavier with extended battery, has only a 1080p screen, and only a dual-core rather than quad-core processor.