If you do opt for OpenVPN, I believe UDP is generally better for performance. TCP support is mainly there for scenarios where UDP is blocked, or on dodgy connections where TCP’s more proactive handling of dropped packets can reduce the time before a lost packet gets retransmitted.

It’s great that you brought up TCP vs UDP. And you are totally right about TCP being a bit slower, higher overhead, but it’s there for situations where UDP is blocked.

I’ve used my VPN at all sorts of hotels, coffeeshops, etc. I’d say 1 in 10 places block UDP (or more likely don’t properly route UDP). If you’re using a SIM card, you won’t have any issues.

However, it’s worth mentioning that WireGuard is UDP only. There are some hacks/workarounds to have it work over TCP, but then you’re going to need to find WireGuard clients that also supports these hacks (which is possible on computers, but harder on cellphones/tablets).

If you want something that “just works” under all conditions, then you’re looking at OpenVPN. Bonus, if you want to marginally improve the chance that everything just works, even in the most restrictive places (like hotel wifi), have your VPN used port 443 for TCP and 53 for UDP. These are the most heavily used ports for web and DNS. Meaning you VPN traffic will just “blend in” with normal internet noise (disclaimer: yes, deep packet inspection exists, but rustic hotel wifi’s aren’t going to be using it ;)