The price should betray that these are 'only' single driver 'phones, but that's not necessarily a problem. The £60 Klipsch Image S4 earphones only employ a single driver, but they still manage to sound good, after all. In fact, it's a little hard to see quite why Ultimate Ears is charging £30 more for its Super.Fi 5vi than Klipsch is for the Image S4s.
Aside from the addition of the aforementioned remote control and microphone, there's little other than styling separating the two physically. The sound produced by each is fairly similar, too, leaning towards warmth of detail rather than crispness.
Where the Image S4s win out, though, is at the high end, where there's noticeably more clarity. The result is that Pixie Lott's voice on the ever-so-catchy Here We Go Again and Turn It Up sound less sharp with these Ultimate Ears 'phones. OutKast's Roses suffered similarly, with the various piano and synth parts to the backing track sounding slightly clipped with the Ultimate Ears. You might not notice if you weren't looking for a difference, but once heard it's a niggle that becomes hard to ignore.
More suitable competition comes from the Etymotic Research hf2 earphones, though, as these feature an in-line remote. Worse still for the Ultimate Ears Super.Fi 5vis, Etymotic's earphones can be found for less, but offer far more detailed reproduction than you would expect from a pair of single driver earphones.
Were these Ultimate Ears earphones cheaper they'd be a much better proposition. iPhones and BlackBerrys hardly have a reputation of stunning audio output, so paying too much more for 'better' earphones when you'll never hear the difference is silly. Currently, however, the Super.Fi 5vi earphones are more expensive than better sounding rivals, which is just silly.
The Ultimate Ears Super.Fi 5vi earphones' only notable advantage over cheaper alternatives is the addition of an in-line microphone and remote. That might have been enough to justify the price hike, were there not better sounding options, such as Etymotic Research's hf2 earphones, which offer identical functionality for less money.