Website suggests the dimensions (240×155×180 mm) and frequency range (54Hz – 28kHz) are identical…
I have loved the sound of my LSX Mk1, and functionality (with macOS volume control) has been great (used with REL TZero).
Reliability - not so much. Owned since March ‘21, they have already had a new network board, which fixed it for a couple of months, but now the network connectivity (wired and wireless) has totally died.
The good news is that KEF (via Sevenoaks Sound & Vision) have agreed to replace them with a set of KSX Mk2. Arrival date tbc.