I used to work for a company that fit meters around the company (Utility warehouse, Npower and Scottish Power) I'm not sure they have those contracts now but I can tell you one thing.
If your a thrifty person and has a good buffer for budget then a smart meter can help.
If your a realistic type of person who knows they spend more in the winter than summer then do not.
Callers are using old people as a quick grab to achieve their targets. I have never not once told an old person their smart meter is essential. Because the older generation will go without heat because it's not a necessity to them. It is dangerous. Tell your parents and grandparents DO NOT get a smart meter.
Other things to note
If you have different suppliers they'll need different meters. But your Gas won't be smart as they just piggyback on the electric.
You can do the same job as your smart meter by physically looking at your meters and submitting the reading for billing. It's just what the smart meters do. It takes 5 minutes.
If you have an old style electric meter (I'm talking black box on a stick) the distribution network operator or the DNO will have to come and FIT a new backboard as smart meters require the tails going in to be on a backboard. (To be fair it's because they aren't safe so don't let kids play with the wires if you have an old style meter)
If your Gas meter is too far from your electric meter it won't connect.
If you live in an area of poor mobile signal (vodaphone specifically) you won't get any signal for them to connect so pointless.
If you have a prepayment meter then it's useful, don't have the stick the key in just one easy card.
If you swap suppliers you can't swap the meters it's all different.
And lastly they are known to cause arcing and sparking which again fire hazard, it's rare but when it happens its terrifying.
Sometimes the old meters are best.
So unless you are truly lazy and can't commit 5 minutes to reading your meter if you want proper bills. Get a smart meter.
If you are on a prepayment meter get a smart meter, the monitor is rather useful as it lets you know how much you have remaining.
If you are old and pay extra in the summer for the winter DO NOT get a smart meter! Don't fall into their ploys!
If you don't like surprise bills around Christmas probably don't get a smart meter, their estimate will be lower than the actual usage if we have a harsh winter and have the heating on 24/7 but you'll pay that back through summer etc...
I wish I could say the meters are great but I cannot they are flawed and realistically everyone being on a smart meter by 2020 is a horrible idea, a smarter Britain is a great idea it's just smart meters are not the answer to it.
If your bill is expensive please try looking at swapping suppliers, it's listed on every bill you get. Money supermarket, Compare the market, Confused to name a few comparison sites.
I was with British gas and we swapped to bulb, 100% renewable electricity and we save around £70 To £80 pm even on estimated bills.
Loyalty isn't rewarded with the big 6 and swap overs are so easy. If you are using estimated bills swap now because you'll be overpaying in the summer so should get some money back 