We picked up our AT5 up in April. It has the Truma hot water as standard. We went to Tasmania in May, June so it was a bit cool. The truma worked well in the shower. The washup water seemed to be a bit cooler. My theroy on this is that the water has further to go in the cold pipes and the stainless bowll is also cold. You dont use as mutch water in the sink to be able to warm every thing up.
The thing that is good is that you turn it on and in 2 or 3 minuites you have hot water. You can also have a shower one after the other. You don't have th wait fot the water to heat up again. My opinion is that they are good. Are they worth an extra $1000 ?