I don't need the last word in timbal accuracy, inner detail, octave to octave balance, etc to maximally enjoy Van Halen - I need huge dynamic range, bass impact, and the illusion of 3D space - that guitar needs to be palpable. The 101s deliver that in a way the SoundLabs don't - at least in my experience with auditioning both.Sound Labs can be quite dynamic with the right amps. Its hard to make them work with solid state because they have a 30 ohm impedance in the bass which solid state can't drive with a lot of power. For this reason a 100-watt tube amp can easily keep up with a 400 watt solid state amp on that speaker!
With the right amp the Sound Labs keep up with mbl101s no worries! They are quite fun to blast Massive Attack or Emerson Lake and Palmer. Not saying the same is not true of mbls by any means. You just have to make sure that the amp and speaker match, which is a different topic!
With regards to soundstage, dynamics, bass impact... you really need that to do classical music and a good deal of folk music.