In case you are tempted to try the current "pattern" heater Matrix from GSF - don't bother. The pipes are ok in size, shape and fit, but there is one small flaw....
The matrix is too long! When I held it up against the Valeo one which I had taken out it was almost 1cm longer!
It's also pretty flimsy and very low density in fins. Not worth the half price of the OEM version.
As I suspected - should have gone OEM as usual - Valeo now on order...