Thanks for the response. Not sure when Northgate are going to release the full web application - we're at a bit of a 'half way house' at the moment. Around 50% of support/complaints about our planning system are related to the GIS bit (non web) - its a bit temperamental to say the least.
Currently most of the system is still on the old desktop version, just letter generation in our TEST has gone to the web app. There was talk from Northgate that the GIS development part would be contracted out to a third party.
But if we could cut out the Northgate bit and go straight to Earthlight to do the spatial searches, plotting, constraint checking etc it would simplify things.