OWNER BUILDER - why not?

Hi All,
We are now having the plans drawn up by a design firm and will proceed with getting some estimates from builders, with the local building industry running full bore I'm expecting pretty woeful quotes. I've been interested in building with CSRs Hebel block system but no local builders will bother at the moment as they don't need to bother. I'm not a tradesman but am pretty comfortable with construction jobs so am now looking at doing it myself as Owner Builder.

Firstly the Advantages, as I see it,
*I'm already doing alot of the running around and investigating option for our own plans so no need to pay a builder for that.
*I'm able to build to a quality rather than a budget
*I can hopefully save a few bucks in labour costs
*I don't have to argue with a builder that doesn't want to offend his tradesmen regardless of work quality.
*I can use Hebel products etc to get the desired home and lifestyle.
*I wont go bust leaving myself in a pickle

Now the Disadvantages
*No building insurance
*May be difficult to get some tradesmen as they are busy with builders work.
*Not much industry nouse, and don't want to make any un(obvious stuffups).ie uncertainty. though this exists with using a builder too.

Can any of you who have been through the OB system point out any more Pros and Cons that I should consider before going down this route.

Thanks Phil

Just found this site and we are about to start off a new build as an owner builder. Hubbie works for a construction company so we have been looking at the construction company building the house for us but then we wanted certain tradesmen to work on the house (including ones from other companies) plus get the savings from buying the materials ourselves - as we know that if the invoice is paid before 30 days there is a huge discount which we would otherwise not recieve!

One thing I have been trying to locate is a good schedule of works, do you know of any good websites or can you help me at all?

Many thanks

Sasha