The cable is thick and somehow manages to be tangle-resistant. The point at which it meets the earpieces feels well made and the bullet-like earpieces are splendidly engineered. They're machined from two pieces of aluminium and feel weighty in your hand when you pick them up. This does translate to a design that's quite bulky - I found that the earpieces completely filled the inner part of my ear, even with the canal flanges pushed right down as far as I could get them - so those with small ears may well want to consider a pair of smaller ear canal headphones.
They are comfortable to wear, however, if you can squeeze them in. The Super.fi 4's differ from Ultimate Ears' more expensive models in that the cable isn't designed to be looped over the top of your ears for a more secure fit, but I didn't find this to be a problem while out and about, commuting on London's crowded underground and walking around the bustling streets. The supplied silicon rubber flanges are light and comfortable, and easy to get used to, though the double flange - the most effective in terms of noise isolation - requires you to push the earpiece right down inside your ear to achieve a full seal, which isn't the most comfortable experience.
Another area where these cheaper headphones can't match their dearer brethren is in the technology they use. Where the Super.fi 5 Pros and Triple.fi 10's use double and triple drivers respectively, the Super.fi 4's are limited to a single armature driver in each earpiece. While there's nothing wrong with single driver design - I've listened to excellent examples under £100 including the now defunct Shure E2c - inevitably decisions have to be made as to how this sort of design is tuned.
As with Shure's low-end headphones, Ultimate Ears has chosen clarity and flat response over the mass-market appeal of thumping bass for the Super.fi 4's. There's no doubt that this results in a much more realistic sound than, say, the CX400, but the sheer power and sound pressure that these headphones are capable of give them a hard, clinical edge that makes them tough to listen to.