As someone who has used windscribe on and off for a couple years I can add a bit of info for those curious.
To start, they claim they run there servers on ram, the same as mullvad, such that when the machine is powered off all logs and other identifying info is lost. In practice we as the user are unable to accurately prove this for any VPN provider, including mullvad. They do log bandwidth usage per account and have a "reasonable personal use policy", you can read more about it here. They have opensourced their app along with a number of other components in their tech stack which is also a bonus.
Windscribe have this kind of endearing and kind of unprofessional leet x synthwave aesthetic going on which I find rather amusing. As well they and IVPN are perhaps the only two on the market that still support alternative protocols like ikev2 and openvpn such that you can use the native IPsec client in Graphene and not bother installing any third party apps. For users who do not mind installing additional apps, they do support post quantum cryptography for wireguard but nothing yet for packet padding (called DAITA in mullvad).
They recently supported creating an account hash rather than logging in with an email and password (but I mean they never verified email addresses anyway lol), and they have for a very long time supported payments in monero, however their website is clunky and in my opinion quite bloated for what it provides. It seems they try to tailor themselves to hundreds of different workflows and, in doing so, appeal to none. You cannot add credit to your account as you can with mullvad, you either pay for one year upfront or monthly, there is no inbetween such as say adding $50 worth of monero and then checking back in 6 months.
For additional not so important features, they have dedicated streaming locations that likely proxy to an internal residential IP, they support port forwarding (I have used it and can attest that it works), they also have a dns content blocker that you can control from their website.
I personally would recommend them insofar as mullvad does not support ipsec (their team has continued to insist they never will and recently discontinued openvpn) and/or google does not add first party support for wireguard to android (their enterprise customers will likely keep using ipsec for another decade). Windscribe is rock solid, most of their servers operate at 10gbps speeds, and their support is surprisingly good in my experience.
I hope this writeup helps someone.