For the record, I very strongly perefer tip-down, but it isn't such a big deal with a smaller knife*. Where it becomes really, really important is when the blade grows to sufficient size that its inertia becomes a problem if it starts to open in your pocket. This is the case with a knife such as the Camillus CUDA MAXX 5.5 with its 5.5" blade. Its designer, Darryl Raalph, and Will Fennell of Camillus have both said that they will not make the knife tip-up for that reason since it has a frame-lock and a ball detente. There are people out there who will modify them, but it violates the Camillus warranty and also, I should think, relieves Camillus of any legal responsibility fr any injuries sustained from tip-up carry.
* Actually, I have had the blade begin to open on my Spyderco Salsa which has a Compression Lock and a 2 7/16" blade and tip-up carry and I was very fortunate not to have cut myself, so I believe, on hindsight, that tip-down is important, no matter the blade size. And, since I would prefer that all of my knives open in the same manner, I would like them all to be tip-down, no matter the lock.