I love the Loxx system and have it on most of my guitars - it's super secure, easy to use, and allows for quick guitar changes. Overall, the system is great but there are a few things to note before making the jump:
* You need to enlarge the hole on most straps to get the locking collar to tighten. On most straps this might involve shaving off a few millimeters of material from the inside of the holes. How easy this is to do depends on the strap and for some thick premium straps only the loxx with the longer threaded mounting shafts will work; the shorter version isn't long enough to allow the collar to reach the threads.. It also means those straps won't work well on normal buttons any longer if you decide to get ride of the Loxx system.
* The screws are larger diameter than most stock strap button screws - what that means is that you need to be careful in switching screws that you don't chip the finish (you need to enlarge the outside of the mounting hole at the very least) and once again, switching back to normal buttons will likely require plugging and re-drilling the mounting holes.
* The button "pins" can cause a lot of wear on the inside of a guitar bag because they're smaller - on a cheaper gig bag you can wear a hole right through the bottom with the pin. If you put on a spare lock (or leave the strap on), this can help.