I have the Granite Gear hip pockets (and shoulder pockets) which I love so much that I can't go hiking without them!
However, your time of 45 minutes to install them is pretty good! Imagine uninstalling them from one pack to re-install them on another! I like the pockets to much that this is exactly what I do. If I wasn't so cheap, I'd just buy a set for every pack.
Note that every pack is different and there may be a few packs out there that the pockets simply don't fit. However, I have a GG Nimbus Ozone, a GoLite Jam, a Vaude Rock 35 and a couple of fanny packs, LL Bean Approach and a Gregory Torpedo that all fit the pockets.
I think that you have installed them correctly. You simply have not yet learned the "tricks" to tightening the hip belt while wearing them.
In your picture, I see that your hip belt is the type that pulls toward your navel. (Like the Vapor Day Pack in Will's review). Here is the "trick." Prior to putting on your pack, set your hip belt length a little larger than your waist. Then put it on and buckle.
Here's the important part: pull only one side at a time ... use one hand next to the buckle to pull the part of the belt that is against your waist toward your hip(this creates slack in the other buckle in your photo) ... while using your other hand on the tail of the strap (the end you normally pull) to take up that slack created by the other hand. Just do a little at a time, alternating between the left and right sides, until the pack is snug.
I hope you can follow this mumbo-jumbo and it helps you to enjoy the benefit of your pockets!