Best type of tank bag?

[Wheelie]

It's been years since I last was in the market - and much have changed. Two new bikes - and I need some advice.

Layered style
I've looked at the Mosko Moto Nomax (on web only, not in real life). 6 layered compartmentalization, charging ports, room for hydration bladder, back pack configuration - it seems awesome!

I really like the idea of having a back-pack that I can use for shopping or trekking. I also want the option to carry an easily accessible fleece jacket, some gloves maybe, and a camera. Will a layered style backpack work for this?

Rigid bucket with hood
This type seems very convenient while on the go - no hurry to zip up. Simply open the lid and grab whatever, or toss in whatever - and go - and zip shut when convenient. You sacrifice compartmentalization. As a backpack it might not be as good.

Soft bucket
This is what I have had in the past. One big room with a map pocket in the lid. One small pocket on each side and one facing me - very convenient. Expandable - convenient.

What I did not like was that the bag became floppy unless completely filled. It was not even remoteley waterproof, and dealing with a separate rain cover is something I prefer to avoid for as long as possible. I've never had a back pack configruable bag in this category, but missed it.

Floating, Strapped Mount vs Magnetic
Magnetics is a no go for me on any bike - due to chafing and how poorly I assume it will sit on more agressive riding - also my GF's tank on her 390 Adventure is plastic. On the T7 I don't know as I am still waiting delivery.

The floating kind - ihow well does it work offraod? I like how easily it comes on and off, and that it doesn't chafe. On the Tenere 700, that has no tank ring, it requires a rig that not only looks very funky, but one which I do not trust. I may go down this route for my GF's 390 who probably would prefer a rigid bucket.

The strapped kind - it will cause chafing for sure, but not as bad as the magnetic I presume. Dealing with the straps is convenient enough for me. This is likely the route I will go on the T7. I am leaning towards the Nomax - if the many compartments have enough give to accomodate larger items in one.

Other desireable features

• Back-pack configurable
• Molly for map case
• Hydration bladder pocket (I don't like carrying it on my body)
• Expandable

Advice please
Bucket with hood or layered with many compartments and organization features, or something else?

Volume? What is a good allround volume - for both trips and every day use closer to home?