Appreciate the response. Interesting to hear it's the 40.2 or the SHL5s. I surely don't think the 40.2 or SHL5 would lack anything in the bass even if the room is large although that might be possible if they are compared to more dynamic speakers. The cut-off point, for me is the C7ES3 as anything below including the M30.1 / 30.2 sounds inadequate in the bass department. The difference is obvious when the speakers are switched, side-by-side in the same room.
If the focus is on snap and kick, it's true that the Harbeth will be lacking when compared to other more dynamic speakers. Hence it is not a surprise that you prefer the Neats and Kudos. Snap and kick are usually in the mid to lower registers. The high frequency response of the Harbeth is also tuned to sound smoother, and this smoothness can be a sound that's pale, dull or slightly lacking in clarity and detail.
The amp surely plays a critical role in contributing to the sound or performance of the Harbeth. I am not sure on the model of the Accuphase amp that was used to drive the 40.2 but if you want kick and snap from the Harbeth, based on my personal experience the higher range Naim pre power would be a better match than Japanese amps from the likes of Accuphase or Luxman which are known to sound smoother. In my case, the Luxman L-590AXII has better refinement, poise, clarity and detail than the Naim but when it comes to kick, slam and dynamic drive, the Naim sounds better. There is a propulsive energy and drive in the bass lines when the Harbeth SHL5+ is driven by the Naim. In comparison, the sound became smoother with reduced slam when the speakers were driven by the Luxman. In the end, it depends on the sound or presentation that one is looking for in the system.