Don't know anything about the wharning but the TDI is not gripped 100% while in the sheath.
I carried the original (small size) just as you described for a couple of yrs...it was OK but not really all I hoped it would be. You can file a little of the sheath to allow better "in sheath grab" and it cuts down on the amount you will have to adjust your grip upon pulling...but there is still a little adjustment needed. maybe you could file enough to not need any adjustment? don't know, I filed and still need to adjust.
I feel honestly that the more a blade takes a special shape the less overall useful it becomes. I really wish they made a stright TDI, I'm sure others love it as is and have zero problems, but we all have opinions and gut feelings. I can't help but think that a stright knife blade/handle set up is always going to be the most instinctive to use.
I know I will be lloking into that meyerco myself...never saw one before, so thanks for that.