I've handled both, and own neither.
I found the LaGriffe _extremely_ comfortable (moreso than the Spyderco SPOT, which seems like it should be more ergonomic), and didn't like the Hideaway at all.
The Hideaway wasn't sized for me personally, but I got to try out about half a dozen of various sizes, and they were all pretty uncomfortable. A big part of the problem is the lack of material in your palm. I don't feel comfortable having only the friction between my thumb and the blade spine to keep the knife from twisting sideways.
The hideaway's no good for me, but I'm in the minority. It might suit you just fine. You might find that a thin cord wrap helps a bit (did wonders for my SPOT). The hard part would be finding the right size for you. The LaGriffe, OTOH, is great for me, but might not fit your hand at all.
For these tiny neck knives, I think handling 'em in person is even more important than usual.