7.3 --> 7.4 C Functions

I'm considering writing some functions in C. This is a collection of
approximately 230 functions, mostly in plpgsql at the moment. Number of lines
of plpgsql is approximately 6500 but that'll include all the blank lines used
for spacing code as well as extra lines to allow nicer formating of things such
as queries. The majority are also not terribly complex involving only a small
number of queries/function calls.

The reasons for changing these to C isn't particularly relevent to the list.
However, all this runs on a 7.3 backend and the priority for changing that is
less that the recoding in C, if that goes ahead. So, what I'm interested in is
people's views on how easy it is to port C functions from 7.3 to 7.4. I know
the elog has changed but that's just a bit of leg work, I presume there is
nothing significant in how to use SPI and the normal sort of tuple manipulation
things.

--
Nigel Andrews