I have been to Whitemead many many times over the last 15 years, and it is a great place to stay.
The pitches are generally a good size and well set out, and most of them are level. The terraces on the hillside have the best pitches, as you get a nice view. Another benefit is that you are further away from the lodges and chalets. Nothing against non-campers, but they tend to drive too fast in that area of the park and stay up late making noise.
On site there is swimming, gym, archery, football, eating, drinking, clubhouse etc. There are two main toilet/shower blocks, which are well looked after. Off site it is a great area for walking and cycling. Gloucester/Chepstow/Newport/Ross/Abergavenny are not far away.
The nearest town (with Tesco, local shops, takeaways etc) is Lydney. Coleford is also near, but doesn't have a Tesco. The village of Parkend is very sweet, with a little shop/PO and a couple of pubs. It also has a very good caravan dealership, which seems strange for such a quiet area in the middle of nowhere.
The only catch is that you have to be a member of the CSMA to go there, or the guest of a member who is there with you. I thoroughly recommend Whitemead Park, and I don't really have any bad things to say about it.