Great set of bags, exceeding my expectations. I bought the Original Bundle in sand-colour. The colour is nice and the fabric sturdy, had a few stains but so far it's easy to clean with a tooth-brush and some mild soapy water. The straps are quite 'shiny' due to the material and I like that - gives the bag a bit more a chic and hip vibe as opposed to 'outdoorsy'.
The Day Pack Original incl. packing cubes are great - it easily fits all my (winter) clothes (3x pants, 2x wool jumper, underwear, socks, toiletries and an extra pair of shoes for a trip of a few weeks - and then I haven't even used the cube attachment. The day pack original (excl cube) is allowed as carry-on luggage - at least I had no issues on a Vueling flight.
The cube seems handy but haven't used it so far - will do so on long hikes in the mountains this summer. Love that the bags stays easily upright when the cube is attached. The orange rain-cover fits nice and snug around the Day Pack and Cube - if you detach the cube there's some room left in the cover still but can be easily filled up with clothes, towels..
The day pack mini, which came with the bundle set, is great and very comfortable. The strap across the chest comes in handy when there's heavy things in the bag - makes wearing it easier on your back-muscles.
It easily fits my laptop, cables, keyboard, mouse, waterbottle, raincoat and then there's room still. I love the roll-top which is handy on those days where you wear layers and it get's hot - it makes it possible to fit a normal sized jacked on top of the things you are already carrying.
As for the sling combo, I've only used it as a mini- daypack so far so not yet as a sling. I'm using the sling mini bag as a purse including the rope/cord - so I wear it more like a crossbody tiny bag. If you wear either the sling bag or the daypack mini on your back it's very useful to have the purse like that, means you don't have to take off the backpack to get to your coins, cards, mobile phone, chapstick, passport, swiss knife (all of this together fits in the sling mini!). I love the idea that it transforms into a hip bag but haven't used it like that yet.
All-in-all the Original Bundle gives me a lot of options for all kinds of situations, on a long travel, weekend away, hike, citytrip..I love that.
I hope the bags last as long as I live, or that whenever a piece breaks down I can re-order it and fix the bag myself - because for a minimalist lifestyle these bags are just perfect.