Are you a web developer (given the nickname)?
If all you want is a deterrent, just put up one of those shields (like those with the ADT, Banham etc logos) at the front of the house, and one at the back. I find unmonitored or self-monitored alarms quite useless because they rely on you, or a trusted person (e.g. a neighbour – but giving keys to a neighbour might void your insurance) being able to attend if the alarm goes off. I am no expert but I get the impression that neighbours or passers by very rarely, if at all, get involved when they hear an alarm go off. Of course this is just my opinion – the UK is full of people who disagree and install unmonitored or self-monitored alarms.
By contrast, a monitored alarm with keyholder response gives you the certainty the property won’t be left in a mess (eg with a broken window through which other gentlemen might enter) for 10 days while you’re on holiday; of course, the risk of this happening is fairly low, and this kind of piece of mind doesn’t come cheap. To each their own choices.
I also think too much security may be counterproductive, because it might lead people to wonder what’s so valuable in your home that you are so keen on protecting. At least that’s what I think when I see a single house with CCTV and metal bars at the windows, in a row of houses with no security.
Ah, it’s not a factor for us, but an incidental benefit of most alarms is being able to track who enters and leaves the property when, e.g. to ensure that the cleaner or the nanny didn’t access the house when they shouldn’t us. Of course it’s also a slippery slope towards spouses spying on each other – I wonder if this has ever been used in divorce cases!
Jokes aside, maybe a nanny or a cleaner might complain that something like Verisure's photodetectors allow you to spy on them? I'm really not sure.
Also, a couple more things that occurred to me:
- You need clarity on call out charges. Banham was transparent in specifying their fees include an annual visit. Amco’s fees don’t, but they say a visit is required every 3-4 years, not every year, and spell out the call out charges clearly. The Guardian published lots of complaints from people who were egregiously overcharged by ADT (things like hundreds of pounds to replace a few batteries) – complaints which were resolved only after the newspaper got involved.
- A smaller, more local company might be more likely to come round straight away if there’s an issue, whereas with a big nationwide company you might have to wait a week before they come in a 6-hour slot which forces you to take the day off work; not sure, just a thought.