this is true. it will be new technology for the UK and will cost vast sums of money (and may not even work too well)
the site where they are based, say Neptune will STILL be set up to house nuclear missiles, so no change there.
the cost of astutes are more than the Vanguard class submarines to build in actual fact
With that. having a mixy-blob of a kind of nuclear tipped missile. the threshold of their use is far lower than unleashing hell on earth (or the threat of)
The boats will STILL act like the current vanguard class in that they go on patrol (somewhere), come back. go into maintenance and go back out.
you will lose the ability to strike anywhere in the world of your chosing with nuc tipped missiles.
the only missile that could be nuke tipped are TOMAHAWKS. they are not sub-sonic. they are easily tracked on radar, the are low flying and the range is limited compared to a trident. They are infact a great deal easier to shoot down than you think.
if you want a nuclear system for the UK. a continuation of the current 4 boat system is the most viable/cheapest option to have a credible force.
and that is not me being biased as I have never served on one do not wish to. is it a fact