Pros: VERY low noise at max speed. VERY good cooling performance. VERY easy to install, VERY cheap for the performance. VERY good for E-PEEN :p
Cons: NOTHING at all. (Should come stock with 3 coolers :p. It's of no use on the cooler, but it will be a great case cooler :D)
It's a big-boy, so be sure it fit's your case. In some setups it will cover the first (or first 2) RAM-slots. You can add a 3th TY-140 (or TY-150) cooler to it, but the results are just a few degrees°C (1-3°C).
Also installed one in my friend his case. His stock i7 920 went into the high 85-90°C range (stock cooler) when encoding movies or play games for hours. And sometimes the PC shuts down for safety. After I adviced him to buy a Silver Arrow he never saw temps higher than 45-50°C doing the same stuff on his stock i7 920. It really is THAT good!!!