Had a very successful day out - thanks for the advice. I took a printout of the Essex CC website in case I needed it, but all the drivers seemed to know about the Essex Saver ticket.
I started at Colchester North Station on a Chambers 754 to Sudbury, a Scania East Lancs Omnidekka, spot on time with a helpful driver who was happy to sell my ticket but wanted to check I was using other operators that day as a Hedingham or Chambers ticket could have been cheaper. I was surprised by the quite a good passenger loading, picking up several passengers en-route. Very nice run through Essex and Suffolk passing pleasant villages. In Bures we passed what I take it was historically the Chambers Depot which still stands, though not used for buses now by the looks of it.
In Sudbury I changed to an Chambers 84, an Enviro 200 Dart, rather than a double deck unfortunately, but to quite a high spec of high back seats with seatbelts. No problem with my ticket but the driver did advise that it was an indirect way to Colchester in case I wasn't aware. Another pleasant run, historically I think at least part would have been run by Norfolks of Nayland until they sold out to Hedingham. Quieter route this time and I was the only passenger at one part and I took this bus back to the centre of Colchester.
A quick lunch in Debenhams - close to the bus stop for my next leg to Clacton. An X76 of Hedingham was another Omnidekka, on time with a welcoming driver and nice journey though not as scenic as my earlier ones. I was dropped of in the centre of Clacton, which is looks to be economically struggling, perhaps part of the reason why First is proposing to reduce their operation there.
Next I took a Hedingham 134 along the seafront to Holland on Sea, another Omnidekka. Very quiet journey passenger wise but nice views out to sea, happy pleasant driver, think he forgot I was up the stair as he was singing as he drove along!
Changed there for a First 7 to Walton, a Scania Omnicity which clearly had had an internal refurbishment so tidy inside and fitted with black leather (or e-leather) seats. I'm not a huge fan of Omnicities - I find them a bit claustrophobic inside, but it was a pleasant journey. The driver questioned the Chambers ticket but then saw it had Essex Saver on it too so was ok about it then.
At Walton a Stephensons Enviro 200 dart on the 105 back to Colchester, it seemed fairly new, driver pleasant and I was waved on after a quick glance at my ticket. Myself and 4 other passengers were picked up in Walton and all traveled to Colchester, pleasant run through Essex countyside.
At Colchester I took a short hop on an Arriva Dart with Plaxton Pointer body to the North Station, friendly driver, scruffy interior of the bus which looked as if coud do with a refurbishment or replaced. It didn't look from the age profile of the Arriva fleet that Colchester is a prime location for them.
So the ticket is great value at £10 I didn't have any problems buying or using it and would certainly buy one again next time I visit the area. Buses all on time and apart from the Arriva Dart all were presented very tidily inside.