It cuts well---kind of "medium-fine" geometry for a hollow grind. Just by nature of being a hollow grind it can bind in some cutting mediums but honestly not a problem that most will run into with jobs they'd choose a folding knife for.
They're extremely well made, and have a strong following for a reason. For me, I have other knives I like better--my old sebbie is now in the hands of my friend who loves it, and the money I got from that sale put a DMK folder in my hand which I absolutely love, so a happy ending all around.
As to tip-up versus tip-down, as other have said, both have strengths and weaknesses. For me, I really do not like or trust tip up, as I have been hurt twice--once seriously, once just painfully--by tip-up knives being partially open when I reached for them. Just the nature of the beast--you have a pivot on the bottom and gravity pulling down. In the one case it was a bit of an unusual incident, as I'd been doing a bit of extreme mountain biking and had had many hard, jarring impacts in a row. The other, however, was just a normal day of walking around and working. Reached for the knife and the tip went on top of my thumbnail, under the skin and, when my hand tried to jerk away when I felt that, cut out sideways. Now I'll grant, it was interesting to be able to pull that skin back and see the actual attachment point of the nail, but damned if it doesn't make you a bit reticent to carry the knife again.
Now, all of that said, a frame lock--at least a good one--is much less likely to open on its own as there's a good deal more friction force on the blade holding it in place. Still though, I've spent enough years now with tip-down carry that tip-up feels very awkward to me. It's all good. Much like a Glock pistol--a truly excellent piece of performance hardware that you couldn't GIVE me because I despise the ergonomics--Sebbies have more than enough of a following to succeed well into the future without me, and I'm sure they will.