When I arrived I went to the Vodafone store in St Julians and got a package. They took a hefty deposit (350 euros which I've just now after a year had added onto my bill, so I'll not be paying for mobile for a while
) but I was immediately able to pair the new iphone with my laptop and get a very usable 3g connection in St Julians. However I thought if I had an ID card I'd get the deposit back - turns out I was mistaken and they keep it for a year.
I'm not sure of the 3G signal in the St Pauls area, nor am I familiar with Melitas 4g dongle package so can't comment on that.
Melita Internet has taken 48 hours max for me to be installed, and was all done over the phone before I had any proof of residency.
Just on a side note, I was warned by multiple estate agents that St Pauls Bay area gets very quiet (aka dead) outwith the summer season, and most people they know moved up there moved back south after 6 months/1 year as they were bored. I have nothing other than their comments to back that up, but perhaps others on the forum might have better experience to comment?