So, to close this out here was my final itinerary with a few thoughts:
2 nights Chengdu | HS train to Chongqing
1 night Chongqing
3 nights Yangtze river cruise ship | HS train from Yichang -Wuhan
Got the 14:40 G train here, we made it with lots of time spare - there were only 3 a day but it wasn't a problem to connect from the ferry which docked just after 1pm. Got a bus from the ferry terminal to the train station (50RMB per person) as the taxis wanted 200RMB for a short trip and we had time spare, bus took about 20 minutes
2 nights Wuhan | HS train from Wuhan-Changsha, Changsa - Zhangjiajie flight
We actually really enjoyed Wuhan, it had a nice museum, pleasant lake to walk around and felt a bit more real. We should however have got an earlier train to Changsha. We got one that arrived at about 3pm, for a flight at 7pm, with the intention of eating dinner in town. However traffic was really bad (over 30mins from the HS train station to the main street) so we actually went into town and then immediately got on the bus to the airport rather than miss our flight. Would suggest either eating near the train station, or arriving into town earlier. I think that the flight rather than train/plane was a good idea
2 nights Zhangjiajie | Train Zhangjiajie to Jishou, then bus to Fenghuang
Bus is now quicker than the guidebooks said and very easy trip
1 night Fenghuang | Bus to Huaihua[/B]
Buses are easier in Fenghuang now as they have all been centralised in a single bus station, taxis in town refuse to use the meter but its only 10RMB/$1.5 for a trip
1 night in Huaihua (before the train) | Train Huaihua to Sanjiangxiang, taxi to Dazhai
The car was 550RMB and pre arranged, which was a good idea as the Sanjiang railway station doesn't have much around it, or that many transport options
1 night Dazhai Terrace| Bus to Guilin
1 night Guilin | river cruise to Yangshuo
1 night Yangshuo | Taxi to airport from Yangshuo, flight Guilin - Yangshuo
2 nights Chengdu

Overall really enjoyed the trip, will return to Chengdu again in 2 years we think, to head north and maybe see Tibet (if BA keeps the direct flight from London)