Give it a "4.5" review for a Kester K100LD in a 1lb spool with .015" solder. Pros: Melts more easily than SAC, flows more like a eutectic, *can* freeze with a shinier appearance. Cons: Still prone to freezing, more like a cold solder joint, especially if you have a dense board with many layers with planes (GND) connected to the pin of interest. K100D is *much* better solder than SAC material which requires a blowtorch to melt and doesn't need to get wet.