I only tried the slim blade at a local store so I can't fully comment on it. However, I've been using my CST L-Trac and its been good to me now for a few months. I use it on my left hand (I'm right handed) and It took about a week or two to fully adjust.
Price:
Got mine for $109 shipped from Proadvantage.
Ergonomics:
Different strokes! For me, it was a little uncomfortable if not used with a gel pad either at the wrist or elbow.
Layout:
One issue that many have is the position of the scroll wheel. Since I have long fingers I don't find it hard to reach when I need to scroll. Other than that the layout is really nice and easy to use.
Quality:
I sweat at the hands and the black shows it. Other than that, pretty solid.
Maintenance:
Maintenance is super easy with only 3 screws required to take off the cover and access the inner workings.
+1 for the trac!