Rebbi, only consider the NAD when you're certain that you need more power. Moving from PS Audio to NAD at the same power levels is generally NOT considered an upgrade. Going from 70 to 150 watts is significant, but not a big jump. If it becomes apparent that you need more power, then a jump to 250 is likely to be more appropriate and you should be looking to upgrade quality at the same time or at least staying at the same quality level. That puts you looking at a bigger PS or a Bel Canto or something along those lines. Since you've gotten into more revealing speakers, the quality of the integrated amp is way more important than it used to be.
Dave
Dave