Like Sliderbass, I own both ER20s and custom plugs. The customs do sound better, more definition mainly. Your mileage may vary.
Keep in mind custom plugs are $$$$$...I paid over $125 and that was years (10???) ago. Add in more money if your health insurance doesn't cover ear checkups. Expensive if you lose them
The ER20s are definitely the best choice in generic plugs...it's worth having a few sets, keep one in every case/gig bag for emergencies
