This comparison is a good illustration of the progress in the PSU field. The two models are comparable in price and formally identical in their output power (in total output power as well as in the load capacity of the particular power rails) but their practical performance differs dramatically.
The two-year gap between them does show up (well, the circuit design of the older model goes even further back into the past: the FSP Epsilon series was introduced in 2005 and its interior design hasn't been revised much since then). The newer model is more efficient, quieter and stable. Considering their comparable prices, the older model has no chance even with its better accessories. The vibration-absorbing pads can't make its voltages stable.
The Silent Pro M2 1000W can be recommended for top-end PC configurations even if you are fastidious about the noise factor. Unfortunately, its cable system is less handy than its predecessor’s. It is the only aspect where we see regress instead of progress between these two products.