Great value. According to clieos review, they are on the same level overall. GR01 has better midbass, but slightly smoothed out highs.
2. Rock It Sound R-50 (link)
A midpoint between B2 and GR01. B2 is leaner on bass, fairly neutral while bright and sparkly. GR01 focuses more on a warmer and well textured bass and mid, but with a smoothed out treble. R-50 on the other hand has the same kind of brightness as B2, with a sense of warmth like GR01 in the bottom ends, granted it isn’t quite as well textured in comparison. Treble is well extended, crisp and sparkly. Mid is well textured and slightly upfront. Bass is well extended as well, with a good sense of body. However, R-50 is closer to ‘B2 with a warmer, better bodied bass’ rather than ‘GR01 with a sparkly high’. As far as overall sound quality goes, it is right about the same level as GR01. Even though it does offer better treble extension and a more upfront presentation than GR01, it doesn’t have the same textured and hard hitting bass to lower mid. This makes it more analytical sounding than warm+sweet sounding, but it is still a very good compromise between the two. Soundstage is quite good. The warmer tone adds back the layers missing in B2 while still retains the same excellent separation.
Pro: Price. Dual driver with a top-tier sound.
Con: Warranty terms.
R-50 is starting to look like a very good deal(sound wise), i did notice quite a lot of build quality issues with it. That could be a deal breaker for me. ( a friend of mine has spent ~500 usd on IEMs in 2 years and they have broken down. RE262 speaker jammed, AT CK10 cabel came off, in a bad way that you couldn't solder it together. Build quality is a must for me)
There has also been reported some channel mismatch, so that you hear instruments shifted slightly left/right.
(R-50 added)Edited by hendric0 - 7/17/13 at 9:21am