i also do chamber and classical work. i tested the wide cards from both DPA and schoeps along with a number of other DPA and schoeps mics. both are very good, but in my testing, neither wide card had the huge open sound of the DPA 4011 standard cardioid mic. i wound up buying a pair of the 4011s, and sold my cmc64s. i just couldnt find the situation where i felt i might need a wide card as opposed to either the 4011 cards or 4006 omnis. i think for near field work (ie, solo instruments in the studio, or on stage micing of small chamber group), the schoeps mk2 capsule is the best i have heard. i think the dpa 4006 edges out the schoeps as you move to medium distances (3-6 meters) for classical work. but overall, i think an ORTF pair of 4011s is pretty hard to beat at all.