I did order F-Stop Tilopa BC with XL and Medium slope ICUs as my own christmas present, although it arrived only few days before new year. And I did this since the zippers of my Gura Gear Kiboko (the original version, sizewise it should correspond to the current Bataflae 32L) are starting to fail. Both bags are have their advantages and seem clearly to aimed on slightly different needs.
First diffence is the size of camera compartments: Kiboko definately offers more volume than F-Stop's XL ICU. With Kiboko, it is easy to carry to carry two cameras with lenses attached, but with XL ICU that requires small lenses and since the lens I most dearly want to carry attached to a camera happens to be Sony 70-400G, this means the space is does not allow second large, gripped body with a lens attached. Also it seems to be easier to take things out of Kiboko's butterfly openings, although the F-stop's opening on the back has the advantage of keeping the backside clean.
On the other hand, Tilopa BC seems to offer more space outside the camera compartments and also number of attachment points for external load. And obviously if your camera equipment fits into a smaller ICU, there is more space for other baggage. With XL ICU there is hardly any extra space in the main compartment of Tilopa BC.
For carrying these bags around, both offer nice harnesses, but I think F-Stop scores bit better backbag experience with slightly more adjustments and firmer waist belt. On the other hand, Gura Gear has superior carrying handles in case you would need to move the bag on hand.
In general, I think these two emphasize bit different things: Gura Gear is great for travel especially when you don't need to carry much than the photography equipment, where as F-Stop Mountain series is as the name suggests more pointed towards for outdoor life where you might need also few other things than just the camera equipment.
And as earlier post mentioned Think Tank bags, I have a friend who has one of their Airport series backbag (I always forget the exact model, might be Airpott Addicted 2.0) and it seems be quite similar to these Gura Gear back bags, of course there isn't the Gura Gear's signature butterfly opening, but otherwise both offer boxy bags with plenty of space for camera equipment and are well suited for air travel (unless there happens to be superstrict baggage restrictions).