I have about 6 pairs of headphones right now and a few that I've had in the past. Of the in ear headphones, the Polks are ok, but the fit leaves something to be desired since the rubber tips don't really work that well and the foam are a bear to fit properly. The sound is mediocre, neither great nor especially bad. Not really worth $100 IMO.
The Sennheiser CX 1.00 are probably the best in ears I have right now. The rubber tips actually work pretty well and do a good job at blocking out 70-80% of ambient noise. As odd as it might sound, you just have to remember to wet the tips (lol) a little before putting them in your ears. Sounds is good, bass is a little strong, but not by much.
The other in ears aren't worth mentioning, but I will say that the best pair of in ears I've ever had were a pair of Shure SE something or others. They had the triple drivers and were around $450ish. The sound was amazing, they almost totally blocked ambient noise and they were easy to transport and wear while working out because they never wobbled out. The only downside is that they were uncomfortable to wear for extended periods of time, 3+ hours. Perhaps they've improved since then.
Currently the pair of headphones I wear most to workout is a pair of Sennheiser HD380 Pro. They're comfortable, sound great and even though they're over the ear, aren't excessively large IMO. Well worth the money, especially since I got them on sale. Highly recommended.
My at home pair are open back Sennheiser HD650's. Extremely comfortable, natural, neutral sound, and with the right recordings I get a similar experience to the Phil 3's in terms of a spacious sound. I pretty much gave up computer speakers and transitioned solely to these headphones.
Only downside to all of them is that they're all wired. I tried a pair of wireless BT headphones awhile back and wasn't impressed with them. I'm sure, as BSA said, the tech has improved, but wireless isn't a huge need for me ATM so I haven't bothered to find out.
