It does look like a good circuit. This proposed raceway is on the MGCC's old land (we still own the hillclimb track there) and we've put in a DA for an extension to the hillclimb too. It will be interesting to see what comes of it, and hopefully the outcome will be very positive for the motorsport community.
I believe the main issue with the Motorplex plan was the intention of also having a drag racing venue, which is not part of the plan for the current owner/developer (Italia Road Holdings). I also certainly hope that at least one of the current proposals goes through.