I save several versions of PSD (16 bit) as I go, and use JPEG for the images sent to models (most of whom don't know if they have Photoshop - JPEG they can always open!). Only ever made TIFFs for an MUA who was emphatic that she needed TIFFs (then rang me and asked for JPEGs when she got them)
I archive the original CR2s and XMPs and most of the PSDs. May archive the JPEGs, but only because they take up negligible space
PSDs are uncompressed - 16 bit x 3 layers x 12Mpixel = 72Mbytes. I wouldn't mind if Adobe made (lossless) compressed PSDs, unless it made them significantly slower to load (I suspect it might make them faster to load, because it would reduce disk I/O - probably dominates the CPU time to compress/decompress/).