The walk we did was ok. South downs way (the route we did) is a well known and well documented way. Hillwalk tours doesn't add much added value to it though.
I realized that the price we payed is fair if you walk alone, but as a couple (like we are) it is totally overpriced. As a matter of fact, the extra price for the 2nd person comes to an extra breakfast and a little surplus for the luggage transfer (far from the extra 900 £ we payed).
My advice: organize the walk yourself, B&B's are easy to find and for the luggage transfer: multiple companies offer the service for 30/35£/day for 1/2 bagages. Result : 50% savings