Hi,
The Lehmann BCL is from my point of view an absolutely stunning amp, provided you like its sound signature. Yes, the lehmann has a sound signature (which is a part of his charm), which is to be slightly on the cool side of neutral. Contrary to what a lot of people think, it is not bright (meaning too much treble), but it is clear (meaning there is more upper medium energy than other amps). It is also very dynamic, accurate and sharp, and at the same time very smooth (it is the only amp I know that manages to combine the two so well).
To sum up:
+ very controlled on everything (bass is deep, never bloated, and articulate)
+ smooth
+ dynamic
++ great resolution
++ holographic soundstage and pin-point precise imaging
- has a sound signature: clear, and on the cool side
- the sound is never bigger-than-life : too much finesse sometimes, you could say
- you may want more bass and treble volume.
Now, the ideal thing would be to listen by yourself, but the headphone amp market is so confidential...