I have a Kershaw Shallot and love it. My knives are well-used. I had one of the older Leek models and after about 1 1/2 years I was having some issues (not locking open). I took it back and they let me trade it in (for purchase value) towards my Shallot. The issues that I had with the Leek have been fixed on the newer ones though. Either way, I prefer to not have the slide blade lock (like the Leek has). I also have an older S&W Pocket Defender that is well used, but it's falling apart, which hasn't happened with any of my Kershaw knives.
As noted above though, you do need to go and handle these different models to see what fits you best. Good luck with your search. I just recently graduated from college, but I always carried a blade on campus.
-Jeff-