I'm not sure where you are seeing ICs (ICs are typically large anyway) but the finals on that Integra amplifier are definitely discrete. You have to remember that the amplifier is quite tall and that the space between the cooling fins on the heatsink are pretty close together giving it a respectable surface area. Onkyo/Integra stuff has been doing quite well on the bench lately. I'm not saying I'm interested in the amplifier personally, but it looks fairly stout to me.
Edit: Onkyo/Integra has been using a three stage inverted Darlington circuit on their higher model receivers and amplifiers for some time now. The disadvantage is heat, but they are extremely linear and work best with a low impedance. It's no wonder that virtually every receiver that Onkyo has that has this triple stage inverted Darlington configuration has THX Ultra 2 certification. Reading the published 3rd party measurements of some of these receivers confirms they deliver massive amounts of power into 4 ohm loads and they often times keep going down lower.
TX-SR805
And I was incorrect, the TX-SR805 has two output devices per channel.