I bought one from 3 a couple of trips to the UK back. It seems to work reasonably well for a cellular internet connection. Latency in the UK is a bit high, but probably to be expected for that sort of connection.

I was able to change the access password and SSID relatively easily following the including instructions (but mine isn't hacked).

For 120 UKP with 12 GB/12 mos of included prepaid data, I'm pretty happy.