I am glad that Ulbricht has been pardoned and I feel like a small iota of justice has been returned to the world with this action.
1) It's safer to buy something online and have it mailed to your house than go pick it up from some shady dude.
2) On the street you would often get duds or spiked product, online reputations were built up over time and important to be maintained (think uber/ebay stars).
Overall silk road probably increased the amount of drug activity but made each incident safer. Not sure what the overall impact would be.