If you're thinking about trying out one of these lavaliere mics, you're thinking about both. Danish Professional Audio is known for manufacturing great microphones for music and some of their lav mics have become very popular in that line of work. The DPA 4061 and 4071 (Used in the musical film, Les Miserables) have made a crossover into location sound recording as body mics. In the following video, I briefly do an A/B comparison with the two microphones.
To clarify, the Lectrosonics SMqv that the 4071 was run through had the Low cut filter set to 35Hz which is its lowest setting. The SMd that the 4061 was run through did not have a low cut filter. The recording was done in a room with a window open and a pretty high amount of ambient sounds from outside.
The Countryman B6 is good. Before owning the DPA's, I thought the B6 was very natural sounding, small, and catches high ends of the voice which are easily lost in body micing. However, it is a very sensitive microphone. The 4061 seems to be much less sensitive than the B6 and even sounds more natural. It catches the high and mids of the voice much better than a B6. The SPL of the DPAs are incredible, much better than the Countryman B6, allowing me to get yelling to whisper scenes clean and not distorted. The 4061 doesn't sound as hissy as a B6 yet still is more effective under thick wardrobe. The DPA wires, however feel very cheap, similar to an ME2 wire, but more malleable. The 4061 is significantly larger than the miniature B6 but not too big; it's about the size of a Countryman B3, whereas the DPA 4071 is slightly longer than the 4061.