A bit of background about me first. I'm fairly new to the headphone and IEM world. Fhe only semi decent set if headphones I have are the Sennheiser HD555s. However, I've been into hifi and home theater for about 10 years now and I have listened to quite a bit of speakers. Currently running a set of Totem Hawks powered by an Anthem MCA30. Quite good for jazz. Not so much for rock. My musical taste is very non selective. I listen to everything from pop, rock, jazz, electronic, classical, opera, rap, r&b to foreign. The only think I don't listen to much is country (although I'm finding that I am starting to appreciate it more and more).
So back to the IEMs.
Purely subjective, but I like the way the CX800i looks. Discrete, clean, professional. The bronze/copper look of the S4i turns me off a bit. Oh well. Looks aren't everything.
S4i by a mile. They just plop in and seal without a problem. The CX800i requires that I keep reinserting and twisting a few times before I can get a good seal.
CX800i wins by a slim margin.
S4i wins. Although I like the look of the remote on the CX800i, the S4i is easier to use without looking.
Ah, this is the part that really matters. I was really hoping the CX800i would top the S4i, but that's not the case. I found that the Klipsch had more detailed highs and mids. Much more detailed actually. With the CX800i, I found that vocals sounded artificially smooth. Almost like it couldn't produce the detail. The highs on the CX800i were also disappointing. They sounded too laid back and powdery. A big surprise was that ongoing that the CX4 to have more emphasis on the bottom end than the S4i. It even sounded bloated. This is surprising given the reputation of the S4i having a boost in the lows and even more so considering Sennheiser is usually know for thin bottoms.
The Sennheiser did have a better sound stage and separation and the Klipsch. The sounds seemed more spaced out and not "in your head" when compared to the Klipsch.
In the end. I think I'm going to keep the S4i as my daily use headphones. While not perfect, they will do for now.
If anyone has any suggestions on good balanced IEMs with iphone controls, please let me know!