I really fancy these, but the negative reviews have been putting me off. I just called safelincs who seem to be their largest distributor and they told me they are discontinuing them due to the reliability issues. They are recommending the ultrafire UB1 instead.
Went for the Fireangel ones. 3 smoke and 2 heat. Cost something like £120 all in. 2 carbon monoxide are on their way too. They were up, fitted, "learned in" and tested inside 20 mins. Whilst I understand that they may not last the advertised 10 years that is a lot of time and money saved. If one goes after a few years I will just replace it.