Calfskin seems to be easier to care for than lamb. However i dont have any lambskin bag (as i'm scared of scratching the leather), I wont be able to make a fair comparison. Calfskin is a little more delicate than caviar. It can handle bumping into things relatively well BUT it is quite sensitive to being pressed against hard object (like a brooch). It will leave a dent the leather where a caviar wont.
I vote for lambskin ..the colour saturation is so much nicer imho...especially if you are getting one in colour ..
Caviar is great but I just love lambskin more..I don't baby mine but it's a mini flap ..so far so good [emoji4]
I'm planing to get a lambskin boy with shiny gold hw so maybe I'm biased..I also am a bling lover so maybe that's why lol