ya, the routine basis is one thing, and I have always wanted to bring my panniers in the tent with me. I know some people don't but I've never understood why, as it usually takes 10 seconds to put panniers on a rack, and I prefer to have my stuff in with me, to pack it up inside if raining etc, no risk of someone being tempted by the bags on the bike.
This velcro system does look more tricky, although that said, my old old front small panniers were designed for mtn biking, and use two velcro strips on straps with traditional hooks on them to securely stop panniers from flopping around. Velcro on back of pannier and on end of straps with hooks-not very clear but I'd have to take a photo to show better--it worked better than traditional systems of the time, but it is a slight pain to use regularly--but the main thing is that the velcro has more or less kept its properties over time, but I imagine that the quality of velcro is a part of this.
As I mentioned, whenever I've seen Arkel stuff, it is really well made, so this should use good quality velcro--plus if the area of velcro to velcro is big and long enough, that will help too for longevity/attaching strength (my panniers velcro section is probably 6 inches long, albeit narrow)
I've always brought my Ortliebs in the tent at night but I am very slow in the morning packing up and am looking for ways to make that process faster as I have a strong desire to be on the bike rather than dawdling around camp. I agree that Ortliebs are easy to release and mount but for me I am wondering if leaving the bags on the bike might be a little faster. For instance, when fishing through my panniers in the tent I tend to take out more stuff than I need and toss it in a corner, which makes packing a little bit slower in the morning. If I could just have the valuables (handlebar bag) in the tent, and the bare necessities with everything else on the bike it might speed things up. I don't think theft would be a huge issue since the panniers themselves aren't worth all that much and they would be loud and time consuming to find all of the straps and remove in the dark (no snatch and grab). I don't know how interested thieves would be in my stove, a few items of clothing, and my tools...
That's good to know about the velcro. I was wondering about that.