Its just such a bad time to sell Maybe. Im sure you'll have more luck come spring when your house will show in a better light, than now in the drab winter. 
The girls in the developers office couldn't give us any reason for the delay Ramsey, but they have said they will email the site manager. Its not that we're going to pull out, its just we want to know. Our house looks almost complete, so it has to be something else. As for your own viewing. I'd say 10-15 minutes shows interest to me. If they weren't interested they'd be in & out in 5 minutes, so fingers crossed.
That is my main concern twinky. As soon as the developer decides our house is done we will be liable for an awful lot of expenditure in the way of rent, mortgage & 2x council tax, plus standing charges at least on whichever property is empty. I'm petrified! It will be bad enough paying the rent, which will be £1100 higher a month than our current mortgage, but if you then add on the mortgage too it will be £1900 a month more than we are paying now for every month we have both properties! 
I hope you have more luck this time 2move. Its about time.
Also, agree 100% with your advice to Ramsey.
I'm sure this will work out for you Toyko. The whole chain seems resigned to the wait for the land registry docs to come through. You could now start to discuss tentative completion dates, or at least dates that don't work for either party, so at least when the docs arrive you can exchange asap without further back & forth.
Congratulations wang on your offer. I'd be chasing your EA to find out what the buyers are up to. Have you even had a memorandum of sale yet with solicitors details etc? Perhaps give them a deadline in which to proceed before your EA chases up the other people who offered.
Welcome happy. Online EA don't have the greatest of reputations unless you live in one of the areas where the market is swift. However, if priced correctly & presented for sale with minimal clutter etc then you have done all you can. For us the online EA fell down at the point of negotiation & sales progression. Japanese knotweed is a bit of a no no tbh, & unless you have great all round DIY skills or know people who do, plus are prepared to live in a building site for years months on end while its being done, then I'd steer well clear.
Glad you're hanging around Flamingo 
A lot to think about there Harriet. The main stumbling block I can see would be doing viewings alongside AirB&B, which would be a huge PITA unless the new place is very local & you have lots of free time. Plus theres the tax implications. May be better for you if they were to AirB&B the place they're trying to sell to you until you are in a position to move in. Either way there are risks. Definitely check with the lawyers.