I own all these brands except the Bradley. I have several Mcustas and Seki-Cut Lums. Here's my take on those three brands:
* The Mcustas are super fine knives if medium duty or less is your goal. They are very gentlemanly knives but are very apt as well. If you get one with a pocket clip it is as deep a carry as you would ever want. They come SHARP and get sharp again very easily.
* The Seki Cuts are great knives too. Their D2 blades rock. My only complaint with them is the use of white nylon washers (in the Lum's) although the knives lock up rock solid in all directions. The other downside is that damned thumbstud. It's a righty only if that matter plus they are very long so they stick out a lot (albeit your thumb finds it fast) and the knurling is brutal on your hand when you reach into your pocket past the knife. I've taken a stone and softened the knurling on the one I carry a lot because it can draw blood. They are very sharp out of the box.
* The Leafstorm is the best built knife of the three IMHO. The ergos are fantastic for a smallish knife. The only downside is there isn't much cutting blade but I've carried mine now for two straight weeks and love it. It came very sharp too.
Check out the Spyderco Sage 2 RIL. That is a very fine knife that kicks a lot of knives out of one's pocket