They are better than nothing. I have one for my XD45 4" compact. It might be because I haven't used it all that much really, but it's still retaining. However, I would not consider it as a long term solution. Cant is sort of doable, if you "cant" the whole rig on your belt. But it's still not great. I feel ok with the trigger situation, but it is indeed fairly soft and pliable. Can't pull the trigger though, although I haven't erally purposely tried to do so.
My biggest issue is with the belt clip on it. The buttom sort of sticks out (it comes down at the bottom so it closes on the bottom of your belt), but it's a "C" shape, so it sticks out a bit. The problem is when sweeping your shirt for the draw, it snags every time. At least it does for me. Doesn't make me feel good about it at all.
The last issue is the basic physics issue with single-point IWB holsters (or possible even OWB holsters). You run into the limitations of physics - it's difficult to comfortably distribute the weight of a pistol using just a single mount point, even on a decent gun belt. I've come to believe that you need at least two points - the wider apart they are, the better (for obvious reasons). This is probably one of the reasons why the Supertuck is spoken of so highly. The size allows it to use clips that are far apart - and so distribute the weight much more evenly, reducing gun sag and the feeling that you're carrying a brick on your belt.
But all in all, I'd have to agree with lima - it's not very good. But then again, for the price, you probably won't get better (but that still doesn't make it good - not sure if that makes any sense).
I tend to use my Smartcarry a LOT more these days, although that one has the issue of digging into my gut while driving.
I need to buy a Supertuck eventually.
edit: had a bit of spare time, so took a few quick pics. Didn't have a tripod with me, sorry.
close up of trigger area
The previously mentioned hook issue. It's not really a "C" - but maybe this will give you an idea of a snag point that at least I experience with it; other people may not.