We can get unlimited for £16/month via uswich. I've used a little over 800GB this month.

I'd move my number from Vodafone to Smarty if Three's 4G wasn't so slow around here. Their 5G is usually 2x faster and available in more places than Vodafone, but I still spend a lot of time on 4G.
My best speed test so far:

It's usually slower (around 600Mbps) and I've seen faster upload speeds (150Mbps), but not bad for £16. I pay 2x more for FTTC and can't go past 65Mbps :-)
Blimey, that's almost Gigabit FTTP territory.
Mind you, I'd be happy with the 500Mbit average I get, if it was reliable. Its fine for downloads generally, but both Vodafone 4G and Three 5G will periodically have issues booting off my AAISP L2TP tunnel which restarts the whole firewall causing connectivity to drop.
Currently paying £16/month on contract but its going up in April. Its kinda insane that long-term contracts directly with the network get price rises while rolling monthly contracts with their resellers generally don't.