I switched from surfshark about 2 months ago because of constant connectivity issues with their browser extension. Nordvpn has fewer vpn locations but they all connect quickly and work well using the app or browser extension. Some locations were slow and hard to connect to during peak hours with surfshark. I got 120-130mb download speed on a fast server with surfshark, I'm getting 180-200mb with Nordvpn using any vpn location, with the same pc and internet service.
I've had no real issues, just some configuration stuff, the tech support staff are very helpful and they actually follow up for as long as it takes to resolve the issue.
I took advantage of a promotion so Nordvpn only cost me slightly more than Surfshark but it has been faster, quicker to connect, and far more stable than Surfshark was.
I can't speak to the mobile experience, I don't use any mobile devices on the internet, but I am using it on 3 windows pc's and it works equally well on all 3.
All things considered, I'm happy I switched.