I recently added a small TNT to my collection too. Mine has lots of holes. Before it arrived, my small Sebenza was my edc every day for the past year.
The TNT really is in another class. I prefer the action, both opening and disengaging the lock, of the TNT. The contoured handles are more comfortable. For me, the small TNT is a better size for edc in an office setting. The opening hole is much more comfortable than the lugs on the Sebbie. The finish on the frame seems like it's holding up better on the TNT, and to my eye it has a much more pleasing color and texture. The pocket clip is as perfect as I've seen, smooth in and out of the pocket, and it's been better to my pants.
I'm not a particularly heavy cutter -- so I can't offer much in the way of a comparison between blade materials. I prefer the flat grind of the TNT, though, and mine came with a wicked convex edge.
On the other hand, the Sebbie is a great knife too. It cost me 30% less. It has that great bank-vault lock-up -- mine still has the best lock-up I've seen on any knife. And (this is a plus) it's easily replaceable in the event of catastrophe -- just call a dealer and get another tomorrow.
It's been said lots before: it's not really fair to compare production vs. custom - there are so many intangibles...
I will say that my dad, who is a diehard traditional-stag-damascus-gent's knife-type, and who was indifferent to the Sebbie and lots of other customs, is very fond of the TNT and I have to watch him around the knife drawer!
If you right click where the pics are supposed to be, you will get the url.