What I Like
Access to the main compartments were good and accommodating since it provide access from either side and the top.
There are plenty of organizational pockets, pouches and compartments so everything had a place and stayed in place.
There are cable pass-throughs between the main compartment, easy access pocket and the front compartment. This allowed me to have my main battery in the inner side pockets of the main compartment then run a charging cable to the easy access pocket to charge my phone and to anything in the front compartment without having the cable getting exposed on the outside. There is no pass-through to the laptop compartment unfortunately so I can't charge the tablet without running the cable along the outside.
It was comfortable to carry even when full. For this trip, I didn't use the waist straps.
What Is So-So
The ability to open up the laptop compartment is meant for the convenience of going through TSA checkpoints faster without having to take out the laptop, but that only works because TSA wants to see the laptop unobstructed. Having the tablet pocket on the side as the laptop meant that TSA will likely ask you to take one of them out so it kind of defeats the purpose. If it is on the opposite side of the compartment like how the Atlas Everki has it then it will be more convenient.
The quick access pocket at the top is not very big and I found it to be a tight fit for my phone. I really can't put much in there if I want the phone to be there. Normally I'd like to stick my phone there when I go through airport security rather then leaving it in the bin where I might forget or make it easier for someone to snatch.
The water bottle holders were a tight squeeze especially if there are bulky items in the inner side pockets. It does stretch so it does fit a typical water bottle but it's not easy to drop-in. For me it was a two-handed operation. I definitely missed the Everki in this area.
The hidden security pocket along the back of the backpack was also very tight. It's good for paper money and other thin items but when I put in my wallet, I found it slightly cumbersome to fetch it back out.
The Travel Pack can hook onto your rolling luggage but it goes on sideways. I'm not used to accessing items from the side but for the main compartment it's fine. For the quick access pocket and front compartment, it feels more awkward and I worried that something might fall out when I open the zipper.
The outside material feels more plastic-like then what I'm used to.
What is Silly
The main compartment has 4 zippers. The two middle zippers can be locked together to prevent it from being opened. The two outside zippers doesn't lock to anything so even if you locked the two middle zipper together, you can still get access to the main compartment with the two outer zippers.
Overall, the Travel Pack performed as advertised. When I first packed it and when through the security checkout, I wasn't as happy with it but it grew on me as I traveled. I had to adjust a bit with how I organize and access items. I would probably sacrifice a bit of form for function such as the bottle holder pocket from the Everki (see comparison between the Everki and TLS here), a bigger quick access pocket and being able to hook to luggage up-right instead of sideways.
I'm not a 1-bag traveler where I would just use one bag to store everything so I don't expect to use it in expanded form much, but even in its normal form there was plenty of space for additional stuff in the main compartment that I didn't use on this trip.