Because the K Series engine installed in the caterham is turned through 90 degrees to run longitudinally what can happen is that a air mixes with  the oil and this gets into the head and can subsequently cause low oil pressure.

<picture of apollo installation>

However after a lot of discussion on the 7's List led me to choose the more expensive route as the best option. The dry sump system basically pumps oil into the engine from a reservoir contained in the bell housing and so theoretically as long as you have oil in the reservoir you are pretty much guaranteed a constant oil pressure no matter how hard you are cornering.  Especially as I intend to track day the car the dry sump system IMO is the best option

<picture of caterham dry sump system>

The Caterham dry sump is by no means perfect due to the fact that if the pump belt becomes detached (snaps, falls off etc.) then no oil will be pumped into the engine and subsequently no oil pressure and one toasted engine.  Added to this is the design of the belt and the pulley (see picture) which means that the belt has been known to slip off at very high revs. However I will not be running to the high revs that can cause this potential problem so fingers crossed I will be OK.  Whatever the dry sump system is superior to the apollo which in terms is better than nothing.

<dry sump belt / pulley picture>

I will be slightly protected by a low oil pressure warning light which should give me a few seconds before damaging the engine, however I know of others who are looking at alternatives to this as the only warning, and I will add any details I can find.

On checking my Pro Forma Invoice it says I have  got a VHPD-Race (GOLD) version of the dry sump, I am unsure as to any differences or if in fact there are any others I could have.