“Switched to these from a TDK BA200 and the difference is phenomenal. I only paid about 80quid more for these than the BA200 with all the discounted sets appearing here and there. The first thing I noticed after getting a good fit was the immense soundstage. They are very detailed and clear in reproducing music, but are rather lenient on most lower quality mp3 recordings. This is a plus for me...” --efgwew
“ These were my sweetest sounding head-gear yet. It would be brilliant all-rounder if it would not require a portable amp for portable use. This is the first reason i left it, otherwise i almost got an ear infection from those foams.., they get dirty in a few weeks of massive use. I recommend them to clean, i boiled them in water. ” --angevoi
“ Well firstly this is not a true iem. The sound is about as great as one could get from an earbud. In my limited experience and without trying the pk1, I would say these are the finest buds you can buy. With that said, these are not for everyone, this is a niche product within an already niche market. I find driving it with my D12 anaconda makes for a pleasurable sound,...” --Jamesdeandoa
“ The PK3 is a great, warm earbud. It does vocals especially well because it is very mid-focused. It has impressive bass extension, not especially strong impact; the trebles are smooth and may roll off too soon for clarity and detail nuts. But the mids are what the PK3 are all about. ” --kmhaynes
Ultimate Ears 350Vi - Headset - Binaural - Wired - Ear-Bud - 20 - 20000
“ Overall I have been satisfied with these phones. I would not recommend paying full price for them like I did. ” --Skoch
PK2 earphones are the low impedance version of PK1. Although not as good as PK1, PK2's sound signature is similar to PK1. You don't have to drive PK2 with an expensive head-amp. If you are looking for something with high performance/price ratio, PK2 might be the best choice.