Family of mine used to own a park home in Margate Caravan Park - they had their own stand and facilities.
The communal facilities are of 3-star quality. The park is not within short walking distance from the main beach. But to get parking close to Margate's main beach in peak time (April and December) is very difficult in any case. You may use this park as a base to drive to other beaches in the vicinity - Uvongo, St Michaels etc.
Whether it is the best holiday resort on the Hibiscus Coast is a matter of taste. If you want to be closer to the beach other parks might be a better idea - such as Uvongo. Other resorts to the South are even closer to the beach - i.e. TO Strand. I've heard that Krause's, which was on the northern part of Margate's main beach, has been sold and I am not sure whether it is still taking bookings.