Amp/Preamps vs. High end AV Receivers


Hi,
I am sure this topic had been discussed exhaustively. I am new to this arena looking for some help to upgrade my Onkyo AV Receiver (135 w/channel). I am debating whether to the AV route or the AMP/Preamp combo. Naturally, I understand that I get what I pay for.

Would appreciate some inputs and suggestions regarding:
1. AMP/PREAMP combo route - 
2. AV route

I am not looking at a huge budget but a decent one. 

Thanks in advance
128x128terrancej
you might try moving in stages by adding a separate power amp and using your avr as a pre--almost all mass market avrs benefit from external amping. you can always get a separate pre later.
When you have separates, the equipment does not have to share power supplies. This reduces intermodulations and for that reason alone allows for better sound.

But there are additional benefits- frequently separates have better power supplies, better heatsinks (in the case of transistor amps), usually better quality parts and overall better circuits.

What is the model of your current receiver?
What speakers are you using? How many? 2, 2.1, 5.1, etc.?
What percentage of your listening time is movies/TV vs Music?  50/50, 75/25, etc.?
Room size?
Do you need video switching form the receiver/separates?

This information will give folks a reasonable chance of addressing your questions. Without it, it's just shots in the dark.....
Thanks for all your responses and let me add more details to get more intelligent inputs.

AV Receiver - Onkyo TX NR809 (Model from 2012) (HDMI, but no 4K)
5.1 Setup
Bowers & Wilkins Speakers and Sub.
Front: B&W CM8
Center: B&W HTM62
Rears: B&W CM5
Sub: ASW610

I watch movies and listen to music + music videos (frequently).

Hope this helps to give more solid inputs.