Been with SlickVPN for several years, rarely needed or contacted support, the only issue I had was to get them to open a port which was done swiftly and has worked flawlessly ever since. The interface is a bit clunky and could do with being made erm Slick? The only issue I have is that my Credit card expires every year - so I have to update that through the online portal but all smooth.
I purchased SlickVPN because they told me they would provide a port forward. After signing up they give me a few bits saying it is a port forward but it is not. There is next to no support at all, and this topic has gone unaddressed by SlickVPN now for days if not weeks. Think it is a white-labeled VPN that they slap their graphics to and grab the cash. They are not a real VPN. Waste of time and money. Also, note - there is no iOS app. MacOS app is pretty limiting.
I purchased a lifetime subscription (core servers) years ago. Service works great for streaming, although a few providers block. The majority that does not block, speeds are great with no to minimal buffering. The PC client is great, android uses OpenVPN and it can be a pain. My records go back to 2017 with them, but I have been with them much longer than that, I have contacted customer support 5 times in 2017 (mainly with connectivity issues and OpenVPN configuration issues), twice in 2019, and once in 2021. Most contacts have to do with Continuous Authentication failures that are quickly resolved. The support staff is friendly and responsive. It is not the best VPN out there, but it is more than acceptable for my needs. If budget is a consideration for you, these guys are worth a shot.