Any recommendations for a reasonably good DIY biscuit jointer? I wouldn't
have asked but, surprisingly, even looking back over the last year I cannot
find a uk.d-i-y post with the word "biscuit" in the subject. Maybe there is
another name for a biscuit jointer...?

There is a massive difference in price between DIY models - which cost, say
£60 - to more advanced models - which cost, perhaps £250. For example,

http://www.screwfix.com/p/erbauer-er...230-240v/33513
£60
http://www.axminster.co.uk/makita-pj...iscuit-jointer £280

The latter is far too expensive for the use I would get from the tool but is
there anything I should be aware of and look for in a cheaper model that
would make one DIY version better than another? The only important setting I
can think of is a fence that can be depended on to remain parallel to the
cutter blade and, perhaps, dust collection would be a boon.

I have seen material saying that biscuit joints are strong but even with the
extra glue surface I wonder what difference a small piece of wood can make.
The biscuit slots don't seem to go very far into the timber to make a really
strong join. I know that biscuits are supposed to be compressed when
manufactured so that they expand in the joint when wetted with glue but,
even so, is the main idea of a biscuit join to *align* boards reliably
rather than give strength?

James