Hi,   I have built many Homes with Dixon over the years and I can tell you the following –

Good – They Build a good home for a very low price (Way below the competitors)
Bad – From when you walk in the door and sign for soil tests, until the house slab goes down is a painfully slow process.
Good – Once the house slab construction starts it goes at a reasonable pace until completion.

Summary –
If you have high holding costs of your land, consider the price you save on the house will be chewed up in holding costs. (I have found that the process can take up to three times longer than with other builders if you strike development  issues.)
But – If your holding costs for the land are not great. You will eventually end up with a cheap quality house. 
I am in no hurry for them to complete my houses asap so the Dixon building process works great for me. ( I have made a lot of money this way) Yes it does get built slower, but usually up to $80 000 less (Highset) than the competitors. 

Other point to note is – If your block is flat with the services in the correct poistion, the Dixon build process will go quite quickly.
If your block has any issues the process will slow and seem to take forever. (Do yuo homework and resolve these issues)

Everyones situation is different so – Take the above points into consideration. Dixon homes work very well for me BUT i can understand why they cause a lot of pain for people in a hurry. I have also found the people at Dixon very good. But , they are bound by the slow redtape dixon building process. But it is that exact thorougher process that delivers those very cheap houses for their customers.

Cheers.