I've had both the Isurus and Brookstone. My pair of Isurus is clearly better than the Brookstone was. I think the Isurus is at home with the $130 crowd like the FXT90, CKM99, FA Tandem, and EX600. Someone mentioned there are to higher tier phones like people are saying. I don't agree since people have only been comparing to mid-levels like the CKM99 and such. They are not a Westone 4 or other high end phone but ~ 8.5 - 8.8 on the Joker scale(like the CKM99) is not out of the question with the right tips getting the best out of them. At $20 I'm not sure if there is not some variation in units so I can't say if some sound better than others. Fit can be an issue as well. I'm sure some get along with the Philips better them being so small that occlusion or other fit problems hurting sound don't occur as with the Thermaltake phones.
I'm thinking I would agree with Dsnuts about the Tt being a bit better. I'll probably have to pick up a pair of the 3850 and compare myself. I had a similar experience with Philips buds not to long ago. Stand alone Philips earbuds for $17($30 regular price) were smashed by the cheapies Philips included with a cheap 2GB player I was helping someone put music on since it was an MTP only device that they couldn't figure out how to load. Not surprised that one of their cheapies smash some of their $30 - $40 offerings.
My most recent good phones are/were a SF 5 EB with Westone cable, SM3, Phonak Perfect Bass(plus a gray filter pack), an EX600(foam removed), and silver cabled TF 10. My pair of Isurus are pretty much just what Dsnuts said they were.
Edited by jant71 - 12/31/11 at 5:36pm