I have a One Hand Trekker (Serrated) from back when I was in high school. I've noticed recently that while that model (black handle) seems unchanged today, other versions have a circular hole as opposed to the oblong hole on mine (this is going by what I see from online dealers like BladeHQ and KnifeCenter). I've always had a little trouble opening the blade on mine one handed, which may be due in part that because of genetics (don't want to go into full detail) I have long nails even when trimmed. I'm wondering if anyone has found the circular hole easier to use than the oblong one? Or is my situation probably the source of my problem...