I used to have this phone and I could never stop using it, but that would have been the same whatever phone it was. I now have the updated 3210 which I think is much better than the 5110. The 5110 was probably the most popular phone out at one where almost everyone used to have one. If you had this on the vodafone network sometimes it was just impossible to get a good signal. But this was the problem with any phone. I would personally vodafone gives you the best deals of prices and stuff but the signal has to be the worst. This phone would not be very good in need of an emergency, as it would probably cut out half way through a very important phone call.
The nokia phones I have to say are the best phones you can get and I would never consider buying any other sort of phone. But if you are worried about getting signal I would say getting your phone on the vodafone tarrif is not the best idea. I would recommend to anyone that they should buy the 3210 instead as it offers alot more. One thing which really did get on my nerves about the 5110 was that when I used to go out in the evenings, the ariel always used to dig into my leg. But the updated version of the 5110 is the 3210 which doesn’t have a big ariel sticking out of the top so it is alot comfortable to be carrying.
If you are a first time buyer of a phone I would recommend the 5110 but also any of the nokia phones as they are very simple to use.