Good question.
I myself had EDC'd a Schrade and a Old Timer combo for 20 years, now they have been replaced with a Benchmade 710 and a 705,(Also i EDC another POS for really crappy work.) the POS gets replaced by a 707 on weekends an hollidays.
Sidenote, had many knives prior to the edc combo's mentioned, but non were as worthy or deserving as them, i retired them when the last time i pulled the schrade to show a clerk at a local surplus, an he kind of was in shock over how good of shape they still were in,(and no longer made) got me to thinking about getting some new ones and here i am today, with more then i can use.
Now, to answer the question, i found over my life, there really are times when the big guns shouldn't be called into usage, due to the company kept or in, surroundings, or even if you feel a little, gun shy in front of others.
Many times i have had to defend my ownership and carrying of said knives over the years, had some good retorts an some bad ones, never lost either to confiscation or whereabouts out of my pocket which includes eyesight i might add.
Although, i tried to never let myself be browbeat over it, except maybe from ol' Johnny law when he knew he had no reason to take them but felt compelled to warn me of them, i simply got tired of going through the,.. OMG, He's got a knife!! thing anymore with some one in the background feeling smart or what have you, this also may include a weird sub conscous thingy, like when you have been heckled about having such a serious weapon on you during your mission to use it to cut something, Do you, Cut towards your body, or your buddy? Lol, maybe its just me, but take note in the future with it.
Final resolve in many of the situations where someone was nearby i felt would suddenly start vocalizing about my knife, i would use the Old Timer, then if someone beaked, i pulled out the schrade with an authoritve snap, instantly shutting them up quite a few times, with some others i just told them, i'd beat em with me fists if they wanted to meet god before sunday.
My bad, i gone long winded an all over the field, the long an short of it is..
I carry small an a large to resolve the different size thing with sheeple an for my needs, sometimes, a larger blade just needs to be used, an for others, something like a ladies finger blade is perfect.
Last note, i have really grown to love the slight recurve, I cAn CuT tHe kIdNaPpErS lEtTeRs OuT Of pApErS wItH tHaT(Kidding), can easily with the tips too, it just looks cooler this way, as i am faster an more accurate this way as it looks like it just being grazed by the edge, but being given enough to cleanly slice through.
And i am curious to hear others reasons, this could be interesting here at BF.
Peace
WR