I think it really depends on what you want in the knife. The 940 has a rather thick blade and tip for it's size. The handle is a little thin for hard cuts. The Barrage is more hand filling (the mini barrage is just enough more handle than the min grip IIRC; although I prefer the 575 in that size range) and is an assist if that's OK with you. The Mini CR has a clip point and feels like a small big knife, or a big small knife with thin handles.
They are all good, but IMO, I would go for (in order):
1. Barrage M390 or S30V versions (what I would probably use the most)
2. 940 (just because it's a legend... although I prefer the 943 with G10 customs scales in that category... makes it even more expensive)
3. Mini CR (personally I prefer my DE Buck knives in this style)
As a side note, my favorite BM's for EDC are the discontinued Presidio (over the new one), the Stryker Auto (handle design is different thant the Stryker 2 manual), and the 590 Boost with Micarta Keyman scales. Also, the 575 Mini Presidio 2 is a favorite when I want smaller than 3.5".
