RoHS does not ban leaded solder. To meet RoHS, the product has to not have more than a certain percentage of lead.
Leaded solder works better than most non-leaded solders in most applications. A eutectic solder is more desirable as it is much easier to get a good solder joint. SN-60, the most common leaded solder, is non-eutectic; its plastic window is a good 40 degrees wide (eutectic solders usually have a plastic window of less than 10 degrees). I would avoid it!
Leaded solder prevents something called 'tin whiskers' which are conductive crystalline growth which can short out connections! This could be an issue in surface mount circuitry.
SN63 (which is not silver bearing) is used for connections not using silver, gold or rhodium.
SN62 (which has about 2% silver) is used if gold, silver or rhodium are present. Most of the 'audiophile' solders are similar to SN62.
Both of the above are eutectic solders.
