That's not exactly true of the NF CPS. It does expand albeit less so than a typical soft point or their bonded cores. The front end does end up wider than the diameter of the shank of the bullet which in turn reduces the penetration.
I'm curious as to why you prefer the A-Frame/TSX to the NF soft point? I've used two of the three and witnessed the performance of the A-Frame in June this year. I've nothing bad to say about the terminal performance of any of the three, really only positive. I have seen evidence of TSX's not opening on the medium and small bores and one reason I prefer the NF and A-Frame.
@Bullthrower338, I spoke to the gents at NF about the CPS a few years back in Dallas. The CPS was developed to create the larger wound channel as has been discussed. It came at the cost of penetration. The question however was how much penetration was lost and could that be afforded over their normal solid. The answer generally was yes. The penetration of the solid with the flat meplat was so good that it was essentially too good. Like complete penetration with an exit from north to south on an elephant good. If you're getting that much penetration, you could almost view it as too much....almost.
Now you may still want that for an elephant, but perhaps not needed on a buffalo. So the CPS was born. It indeed penetrates less than the regular solid, but still has great penetration but now with a larger wound channel.