Alright, so now I've had this backpack for a while and I've put it through daily use to and from work and for use in an urban environment such as London. This backpack is awesome, end of review.
But yeah, it is a really awesome backpack. As my other two F-stop bags, the quality is top notch. The Guru is smaller than the Loka, and pretty much perfect for day trips especially in urban areas where you just need an extra jacket or something similar. As a day pack for use in the outdoors I don't feel that it's quite big enough, if you want to bring food, clothes and things like that. But if you take out the ICU (Internal Camera Unit) it would be, but for me that would be to go against the whole point of buying a camera backpack of this sort, but it's still an option though and easy to do.
For anyone not being familiar with F-stop bags, the following is a summary definition. Kinda...
All bags in F-stop's Mountain Series can be described as being empty shells, and then you use a separate camera unit called ICU (ICU = internal camera unit) that comes in different shapes and sizes.
This means that you can customize how you want your backpack to be depending on how much camera equipment versus other equipment you have or want to bring.
For the Guru I've chosen a Small Shallow ICU for my Fujifilm cameras, because I want to bring other things than just camera gear, bigger one would mean nearly no space left for other things inside of the main compartment.
An ICU has removable inner walls so that you can customize it, like camera bags normally have and are as good as any other that I've tried.
The Guru follows international luggage dimensions, but you can easily take out the ICU and bring it into the cabin if you would need to check in your backpack on a flight.
Well, on with the description of the Guru. In the main compartment (where the ICU goes) there's also a pocket that can be used to store an iPad or a smaller, maybe 13" MacBook or similar laptop (check F-stops website for exact info on that), or to hold a hydration system like Osprey or CamelBak. I have an Osprey Hydraulics 2L, but I haven't tried if it fits, I might do that eventually and update this review, but since I have this backpack for more urban use and not nature hikes, I simply haven't tried that. It should be used with the optional waterproof bag that can be bought and hung inside the backpack (for extra leakage protection). A special opening marked H2O where you pull the hose out and attach to the right shoulderstrap through some mesh and a velcro loop.
You've got an extra (large) compartment with different pockets to keep daily general stuff or extra batteries, cleaning cloths, filters and those things. There's also a key holder in there. On top of that there's an outer compartment to store, well anything, but would hold something like a rain jacket for example. In addition there are two exterior mesh pockets, one on each side where you can have water bottles or put down tripod feet into.
There are compression straps on both sides and also on the back, which can be used to attach a tripod and/or skiing/snowboarding/hiking poles/snow shovel or whatever you need.
In a number of places there are loops where you can attach additional straps (called GateKeepers which is optional) if you want to secure a tent/sleeping bag/sleeping pad or similar.
In addition, on the waiste belt, there are anchor points compatible with the MOLLE system (Modular Lightweight Load-carrying Equipment), which for example the police and military use and there are a plethora of bags and other things that you can attach there if you want.
D-rings are also available to offer yet another way to attach things to the backpack.
Adjustment possibilities are many, and the support system is great and I think that it fits most people. The good thing with all but the Kenti backpacks of the Mountain Series, is that the opening to the camera compartment is towards the back, which means that you can put down the backpack where it is wet or muddy without getting it on the shoulder straps or on the back and if you're in an urban area, your precious camera gear is safe from pickpockets. All zippers are sturdy YKK.
If you need something for urban use, or of course in the outdoors, check this bag out. If you need room for more gear, well you could get a slightly bigger ICU for this backpack or maybe you should look at the Loka instead (look to the right for the link to my Loka review) or maybe you need something even a bit smaller, and something that looks even less than a regular photography bag/backpack? Then have a look at the F-stop Millar Series (look to the right for the link to my Brooklyn Sling review) of bags/backpacks.
Even if the Guru and the rest of the F-stop line is outstanding, things could still be improved.
The backpacks doesn't come with a rain cover, though it's probably not very often that you need it, but still. F-stop backpacks are quite expensive and a cover could or should be included in the price, but then again, quality is usually not cheap. And also, it can be quite hard to even get your hands on one of these backpacks. The people at the customer service are friendly, but otherwise the actual service (as in delivering orders to people) still needs to be improved.
But as a conclusion, these backpacks (including the Guru) are as good as it gets. If you're a serious shooter, do yourself a favor and get one.