On the other hand the sound of iFi Power Elite is more exciting, faster if possible.
Both are good options. Perhaps the iFi is more appropriate for digital devices like the router.
For digital gear, the most important power supply consideration is low impedance. The lower the impedance, the better the supply will do at meeting instantaneous current demands. Noise is generated inside the component when those demands cannot be met.
What I look for when assessing a power supply is some mention by the manufacturer of regulation or of low impedance. Farad mentions this as do all the better audiophile power supply manufacturers.
Some manufacturers aim instead for low noise. The more affordable power supplies like the Sbooster supplies is an example. It looks like this iFi Power Elite is another. These can be and usually are a clear step up from an SMPS. That’s usually exactly what they are aiming for. I’m dubious though that these can be competitive with power supplies that aim to be both low in noise and low impedance. But as I have no experience with this power supply, it wouldn’t be right for me to render judgement. It does look like a good option for routers as they don’t really put up demands for instantaneous current. As such I appreciate you mentioning it.