I was all set to replace the gravity-fed HW system in the house I am
about to move in to with a megaflo (or some other unvented system), but
research on the net on "mains pressure hot water" brings up lots of
mentions of thermal stores (aka heat banks), and these would appear to
be a recent development, with many advantages over megaflos (as
described in
http://www.gasapplianceguide.co.uk/M...r_Systems.htm).

If these are so good, and a recent development, have they made megaflos
obsolete (at least for domestic use)? Would somebody like to argue the
case for a megaflo and against a thermal store?