@trolly I would try one out first before parting with cash ...my opinion THEY SUCK!!!
CRAPPY SPEEDS with CRAPPY CONNECTIVITY and holding that connectivity!
they are usually limit capped this includes any videos watched any surfing done and even antivirus updates that can be upto 20mb a time if its updating the program too ...add to this the DONGLE software even wants/needs updating now and then adding to this capped limit!
best bet is to get a laptop with wifi in and find a wifi hotspot they are cheap enough to use for an hour FAR CHEAPER than a CRAPPY DONGLE!
some library's allow free wifi access so long as you don't abuse the traffic used
most companys give a NOT SO FREE laptop to get you to sign up only to realise that your now paying anywhere from £30 - £50 a month for a less than dialup crappy speed and capped from 700mb usage to around 1gb of usage per month for an 18 month contract!
Ask yourself can you justify the price per month for crappy speeds (yeah I like the word crappy!) would you really use it enough to warrent the price per month they demand!
on the other hand you can buy a dongle outright usually anywhere upto £100 minus the laptop and pay as you go again still not cheap and guess what STILL CRAPPY BANDWITH!
I would definitely consider looking into coverage even ringing the provider that's responsible for the contract/Dongle access to be sure! otherwise you got one for NOTHING!
my personal view and thoughts of DONGLES ... I HATE THEM!! .. AVOID get proper internet access wherever you can its more reliable its FASTER and its CHEAPER!!!!