A quick heads up about international data if you're traveling through the UK/Europe soon

Just got back from a multi-stop trip across Europe and wanted to share something that completely caught me off guard. If you still rely on your domestic carrier's daily roaming passes, please double-check the fine print before you leave. I used to just pay the $10 a day fee for convenience, but on day four of my trip, my data suddenly dropped to a crawl. Turns out, even if they promise "unlimited" roaming, they aggressively throttle your speed down to basically unusable 2G network levels after you hit a tiny daily cap.
I couldn't even load Google Maps to find my train platform in London, which was incredibly stressful. A guy at my hostel told me to stop wasting money on roaming passes and look into dedicated international data SIMs instead. I ended up getting a connection through a global data provider just to get through the rest of the week, and the difference was night and day.
If you're planning a trip, save yourself the headache. Don't trust the big carriers' marketing. Either buy a local physical SIM when you land or set up a dedicated data plan beforehand so you don't get stranded without maps in a foreign city.