I was just here yesterday for the second time. My friend likes this street because she can buy gothic lolita clothing for relatively cheap prices. Basically, the good and bad of going here:

Good:

great for people watching
relatively cheap prices (in comparison to other parts of Tokyo)
amazing daisou (100 yen store)
some American stores (like Claires, Body Shop etc)
many store people speak English
excellent supply of shoes, bags, perfume, clothing
amazing crepes on this street
about 2 minutes from the Harajuku station

Bad:

Sundays are especially bad; very hard to move around
stores are small, so don’t have a lot of luggage with you

if you look foreign, you will be targeted by salespeople (although, I’ve noticed that it’s not as bad as other cities around the world)

I always like going here, but I can only stay in this area for about 2 hours before I long for my quiet mountain town.