If the shell fit of your boot is spot on, then custom liners can be the icing that was never put on the cake.
Then again, maybe you don't like the icing.
Phil P. will ring the praises of the Raichle Thermofit liner that comes with their boot. I use a Raichle Thermofit in my tele boots. Love 'em!
I wanna get foam injected liners for my Lange L10's.