I use outboard amps.
I was disappointed to learn that despite being billed as "full set of preouts" there is no way to get the Dolby Atmos channels on this unit. Anyway that doesn't really apply to you but I thought to mention it.
Many people consider adding outboard amps without fully understanding the pros and cons. I made a thread
about it you may consider examining.
One of the main issues I have is that people often are sold on using an outboard amp for added power output without fully realizing how measly it might be. For example, say you have an AVR with a rated output power (20Hz-20kHz, 2ch driven) of 95 W per channels (8 ohms, 0.06% THD) and are considering an alternate amp with 140W/ch under the same conditions. How much higher output can it achieve? The answer is a rather insignificant 1.7 dB. [Check my math here
] You can easily experience what a change of 1.7dB means by rotating your current volume knob down and then back up by 1.7 dB [Well, you are locked to .5 dB steps on this and most other units so either do a 1.5 or 2 dB change]. Hear that amount of change? Not much, is it?
Generally speaking, here are what differences are meaningful in actual use:
= hard to even notice with some music but easy with the right kind (or test signals designed to make it easy to hear)
= detectable but unlikely to make a consumer looking for more power happy
= more easily detectable but still unlikely to make a consumer looking for more output power happy
= easy to hear but still not all that much, IMO. This value, 3dB, is important to memorize, however, because it's the gain reflected by doubling an amp's power, i.e switching from say 95w/ch to 180 w/ch.
= an appreciable increase in SPL, often described by listeners as "doubly loud", it reflects a change in amp power of 10X, that is, switching from a 95w/ch amp to a 950 w/ch amp.
Decreasing the seated distance to the speakers or switching to more sensitive speakers are two other good ways to improve output.