We went for 10 days last August, and it was one of our all-time favourite camping trips .
We were in the field on the right hand side and there was loads of room, despite it being fully booked. Don't remember it being that much of a trek to the loos - in fact IIRC there were 4 toilets in our field, 2 blocks of 2 at either end. Showers I think we had to walk to the next field? We managed fine without bikes anyway!
Walk down to the beach was do-able (DS was 3 and DD 5 at the time), the first time we scrambled down and thought never again... and then we found the steps! Views are amazing from the top field. There was some sort of festival on at Weymouth while we were there with fireworks, etc and the Red Arrows flew over the campsite as part of their display - DS loved it!
We walked to Weymouth along the coastal path a few times which was nice. There was also a regular bus service from the next cove along (Bowleaze I think?) if you didn't fancy the walk. Couple of cafes etc on the way if you need to stop (we got caught in a torrential downpour one day so were very glad of the cafe!!).
We had quite a bit of rain the first week we were there so the site was a bit boggy - didn't want to get stuck in the mud so we were avoiding using the car where possible! Oh and our exhaust had fallen off on the (bumpy!) road into the site , which didn't help. Kwik-fit in Weymouth did a great job though
We had a campfire whenever we could - for us that's one of the best bits of camping, so that was a definite bonus! There are lots of hay bales around that you can get to sit on - it was great! The kids had lots of fun rolling around a big old metal barrel thing(silo?) around the field! Loads of kids around and masses of space for them all to play in - it really is fab and we will definitely return!
Trying to think what else we did while we were there? Lulworth Castle & cove, Durdle Door - good days out!
I'm sure you'll love it!