In terms of Meelec's lower IEM's, they're more fun sounding and detail is slightly above average with average comfort, such as the M9 and the SP51, but the A151 manages to surpass with the Siren Armature Style it has. Comfort: I have tried the stock tips and works the most is Medium Single Flange. It sits firmly in and around my ear with very little problems. Isolation: In this department, it's nearly as good as the comfort. I use this in my daily commute in New York City and it blocks out -26db of the sound around me and even at Times Square in the Morning Commute. Build Quality: With the High Impact Deco Housing and the glossy finish, it not only feels awesome, it looks awesome too. It withstood some minor accidents and with the braided cables, it can withstand some abuse. Although what irritates me a little is the I-Plug. The A151 could've incorporated the L-Plug style that Westone or V-Sonic and that could've put the A151 slightly ahead of my GR06. Accessories: In terms of this section, it's alright. The A151 comes with a clamshell case, 4 pairs of eartips, 1 pair of small, 1 pair medium and 1 pair large eartips, 1 pair bi-flange and 1 pair Large Tri-Flange. Sound Quality: After listening to the A151 for at least 25 hours, I find two words that come to mind: Accurate and Detailed. It's not more detailed than the GR06, but at least it challenges the GR06 in terms of Midrange. Bass: In this department, there is low quantity of bass and the depth isn't that impressive, but the detail is near the GR06, which is very good. Hardcore Bass Lovers will find the A151 quite distasteful l, but impact is pretty fast. It's much faster than the GR06 and at the same speed as the Brainwavz M5. Midrange: Very nice vocals, but it seems a bit dull at times (depending on the bitrate of the music. Works well with Classical and Vocal Trance, but not good with Rock/Metal at the upper Midrange and Lower Treble, due to lack of crunch and crispiness. Treble: In comparison to the rest of the frequency, it's the most laid back part of the entire frequency. It's not energetic and has a tiny bit of crispiness with most genres. Its' energy is barely felt with the best bitrate files and even with FLAC files, unless if you have a headphone amp with Gain settings and controls. Besides, I seriously dislike edgy and uncontrollable treble anyway, so I find this really good. Soundstage/Instrument Separation: This part of the A151 is very good and it's very good at for under $100. It may be one of the best, especially after amping. Although at lower bitrates, the instruments tend to over lap a lilttle, which makes the imaging a bit blurry at times. The width is average and so is the depth, otherwise I'm very happy about this Category because it's one of the most impressive parts of the A151. Conclusion: In terms of accuracy and detail under $100, the A151 is one of the best, especially after amping. The bass is pleasant and just the right amount, while the midrange and treble clear and articulate. The accuracy is the most impressive aspect of the entire sound of the A151. The accessories, comfort and isolation are also quite formidable for under $100. For under $100, this is begging to to be grabbed.