Read here for instance: https://www.androidauthority.com/snapdragon-x-elite-benchmarks-3380426/I'm not sure about this, but two power profiles were mentioned (80W and 23W), which sounds more like total SoC power than total device power.
The performance numbers released last year seems to suggest that it's similar to a full M3 Pro, which has the same core counts (12 cores). Even 80W SoC power does not sounds too bad as it's the peak power and we don't know how much power it actually consumes when running something like Geekbench. M3 Pro is ~30W when running some CPU benchmarks.
Of course, the main problem Microsoft will face is software. Right now most software on MacOS are already ported to ARM, but the majority of software on Windows aren't. This will take time.
Qualcomm had two Snapdragon X Elite reference devices to test, spanning high-performance and lower-power use cases. Configuration A targeted an 80W total device TDP, running a QHD screen and 64GB RAM, while config B is a more power-efficient 23W implementation with a 2,800×1080 display and 64GB RAM.
Anyway as usual I pick that with a grain of salt and will wait for consumer devices.