I bought this as I was getting back pain and a bit of stitch-like lower bump pain at about 23 weeks, particularly when walking the dog for any length of time. The belt looks complicated at first but isn't really. The strap which goes under the bump is very comfortable, and easy to adjust, and I have worn it alone for a bit of bump support.
The biggest problem is the back support. Although it is really comfy at the back and can be pulled tight to give as much support as you need, it attaches to the under-bump strap round the sides with Velcro. The problem is that is you are small framed to start with (I'm a pre-pregnancy dress size 10, sometimes 12), you pull the sides in towards the front but the hard plastic Velcro of the back support doesn't completely fit onto the under-bump strap which is narrower at the front, so some of the Velcro is free to irritate your skin - very uncomfortable. It was also pointed out by another reviewer. I finally solved this by attaching a couple of strips of corresponding Velcro (from my sewing box!) across the free Velcro bits, i.e. I made the under-bump strap bigger, if that makes sense!
It should be OK I think for those who are a bit bigger than me, but can't be sure.
It's now very comfy, and really useful when doing longer walks with the dog - and has definitely helped with the aches and pains. It does show a bit under my work clothes, so I don't wear it all the time, and to be honest feels a bit bulky and unnecessary when sitting, so at the moment I use it mainly for planned walks. It is very adjustable, so I feel sure I'll use it even more as this bump gets bigger or the muscular pains get more frequent, and I might not need my Velcro add-ons by then..
I also bought an elasticated support belt to more discreetly fit under clothes for everyday use, and though is more discreet, it definitely doesn't provide as much support that this one does.