I wouldn't bother myself. We had one after being told we 'needed' a smart meter. Its beyond crap and does absolutely nothing to help save any fuel.
The box/viewer I have is inaccurate because its too far away from the actual meter and its giving the reading for next doors usage instead as their meter is closer to our reader than ours is. Theres nothing we can do about it either, its down to the position of the meter and the shape of the house.
You wont actually know whos reading you are getting either without trying it. We only noticed when the house was empty of children and we were sat reading on a bright warm sunny day and it suddenly showed red for high usage. There was nothing switched on in my house but I could hear my neighbour hovering. When they stopped hovering it went back down to green.
Also the cost of running your little smart box which tells you how much you have used is around 2p a week. OK so 2p isn't going to break the bank but its still not free to use it.
The cost of the smart meter is added on to your usual utility bills and spread over a number of years. So again theyre not free.
If you change suppliers many new suppliers cant use the smart meter you have installed so they will need to change it again. If you are keen to save money and like to switch suppliers frequently for the best deal then that's an awful lot of wasted smart meters being installed then removed.
The only good thing about them is that since having the new smart meter installed our bills have fallen by 40% because the old meter was faulty and they refused to fix it before.
Funny enough they cut off our electricity and gas to find out why our bills had dropped so dramatically (they thought we had hot wired it and bypassed their meters) , then they asked for us to continue with the old direct debit monthly figure until they could sort out why its such a huge reduction in cost. It should only drop between 2 and 5% according to them.