Hi there... We have purchased the 18.58-1, which we saw at the Brisbane show.
We went in to buy the 17, but found the 18 which had just been rushed through to appear at the show.
To be honest, we have had a few issues, 1 of which being the new fridge. Loved the idea of the 2 door large 185ltr Thetford fridge. However, after the show, I visited it again at the Brisbane dealership. It was then I noticed that both models, the 18.58-1 & 18.58-2, had a huge scratch in a semi circle as the fridge door opened. I found that the pin on the right side of the fridge door (pin that comes on the fridge from the manufacturer to change the door swing side), even though Jayco fit it to only open 1 way, the pin is still there. Would you believe I had a huge battle with Jayco, after I noticed it. I asked if I could have the fridge raised because if this issue. My reply was, NO we can't.
Anyway, long story short, they have now come back and said that it is now recognised as a fault and it will be sorted. They still haven't said how it will be sorted. But as long as it is, all good.
Over all though, we like the layout better than the 17.
We too have to have it rated at under 2500kg tow rating. This limited us a heap with what we wanted to add to the build, but just a little tip for you. Jayco allow 400kg for payload. If you ask the question, they will reduce the payload slightly so you will be able to add a few extras, eg. Extra water tank, gas bottle, extended drawer bar...
Hope this helps.....