the general consensus around here is that ear plugs are a must. I wear them sometimes and have no problem hearing traffic. You still hear the same amount of things, it's just at a lower level. How much traffic you think you have hear over that exhaust anyway?
Right now I just use some of those foam cylinder ear plugs. They work but are a serious hassle. They take so long to expand that I usually debate whether I want to wear them because I've gotta stand on the sidewalk with my fingers in my ears for so long waiting for them to expand and then once they're in half the time they get pulled out when I slide my helmet on. I plan on picking up a pair of molded ones like you posted. That price seems pretty decent. I saw a pair in superstreet bike that were recommended but they were $100 so I've been a little scared to check on other prices. I'll probably buy 2 pairs for that price though, one for normal use and the other to mold in a pair of ear phones(like the picture shows with the string he used). That way I can use the GPS on my phone if I'm taking a road trip or anything like that.
The only downside I've found to using them, aside from the hassle of putting in the foam ones, is that they're awful for around town. When you're on the bike and it's running over 3k rpm most of the time they work great. If you're in stop and go traffic, like I usually am since I live in the city, it gives me more of a headache to wear them than to not. You don't hear engine noises as much, but you hear anything your body is doing. You can hear your helmet on your head, you can hear when your foot hits the ground or you move around on the bike, and the shaking you do when the bike is under 2k rpm is definitely worse. I'm not sure how to describe it. It just sounds like internal noises are getting trapped in your head. I get the same noises when I wear the ear muff things when I'm doing shop work. Either way, definitely get a pair, and I think you'll be much happier with the molded ones as opposed to foam... and thanks for the link! You saved me the hassle of having to find a pair myself.