We're having an active discussion on Seek Outside here---
https://backpackinglight.com/forums/...tion/#comments
Regarding pack access at different levels---It does have top access of course and if you pack carefully you can plan to have what you need at the top---water filter, snacks, rain jacket etc.
You link pic shows the Unaweep with an added Merlin daypack---used as an outside pocket (not part of the Unaweep purchase). I would probably get this daypack to boost pack volume. Having this daypack would offer separate outside access to gear of course.
And currently there IS NO top lid option, although I hear a lid is coming. The Talon sheet is also optional and not part of the pack. It's a good option I think if you want to sandwich in bulky items like clothing and a sleeping pad. But be warned, the Talon does not attach using the pictured side release buckles---and instead they have switched to Gatekeeper connectors.