Reddit mentions of Manfrotto MB NX-BP-VGY Backpack for DSLR Camera, Laptop & Personal Gear (Grey)

https://www.amazon.com/Manfrotto-MB-NX-BP-VGY-Backpack-Personal/dp/B015RA4L52

I've used this for a while. I can fit my G9 plus about 4 lenses depending on size. Typically I have one zoom and two or three primes. I can fit my laptop, sketchbook, and still have a lot of space left for other things such as sd cards, lens filters, extra batteries, and other misc. stuff that I may or may not need depending on the day. Another bonus is that there's a strap so you can also carry your tripod with you. I used this backpack while I was in school and now I use it for work and I find it nice to have my work stuff and photography stuff all in one place. Like you, I'm not a fan of dedicated camera bags.

A cheap but well made bag id recommend is the:

Manfrotto MB NX-BP-VGY

Its on sale on Amazon for US $73.00 (down from $90.00)

https://www.amazon.com/Manfrotto-MB-NX-BP-VGY-Backpack-Personal/dp/B015RA4L52

Also available on Amazon Canada for CAD $80.70

The bag has room for a camera, a lens and batteries as well as room for a laptop and a compartment for papers and maybe a thin book or two.

I would double check the size of the camera compartment with the size of your camera just to be sure it fits.

or, if you don't want to spend $260, I have this $70 Manfrotto. Works pretty well for my needs. Can carry the tripod/laptop as well. - https://www.amazon.com/gp/product/B015RA4L52/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1