Summary: This power supply is listed as one of the better series out there, so I purchased it. It provides great, stable power to my new build. It is running with an i7 processor, Asus Z87 expert motherboard, 32GB ram, EVGA GeForce 770 4GB, an SSD, a HDD and a samsung optical drive. No problems here. On the semi-modular: Four cables are hard wired into this supply. The 20+4 pin motherboard connector, the 8 pin CPU connector, and two PCI-E power connectors.
Summary: Corsair once again delivered a great product for me. It's very quiet, in fact my case fans are louder and they have an even higher diameter. Everything working as intended. Will post again if any faults occur with the product.
Summary: Update (3/27/2013): After the RMA, I received a new HX850 with a their "new" fan curve. Turns out that the fan doesn't spin at idle-load and spins up loudly then turns off. Spoke with Corsair technician supervisor today, and he admitted that it's a known issue and they're upgrading me for free to an AX850.
Summary: Perfect stable power draw, looks nice, high quality sturdy build. Everything you could ask for! The price is definitely worth it for this beast. It is powering a rig with a 2500k cpu, 2 gtx 470's in sli, two 4gb ddr3 1866 ram cards, 2 hdds, an ssd, a bd/re drive, a bunch of case fans, and all kinds of usb devices. There's not even a hiccup. My old PSU was the sparkle 1250w.
Summary: I paid a lot for this power supply when I ordered it. It had excellent reviews, and I've been using it for over 2 years now and it's still going strong. Very quiet, and I'm sure my system's stability has been a testament to this component's stability. Corsair makes some of the best power supplies, and I felt for a performance desktop, it was worth the added cost.
Summary: My computer used to shut off during power-hungry processes such as video games, video rendering, etc. When I replaced the PSU, everything ran perfectly, without overheating. I love how they ship so quickly too. I live in California, and they shipped from Nevada, almost immediately after I confirmed my transaction. I received the package within 13 hours (with two day shipping!).