You should do a search on this mate, Shrek I recall gave some info. WPI has less carb and fat content, slightly higher protein per 100 gms, and is more expensive.
Guys who are careful about cutting sometimes prefer it to WPC if they're prepared to pay the extra. Lot of guys on the forum go with WPC however. Taste-wise the WPC is a lot sweeter.
Wow...peptides..WPC has much longer chains of amino acids and can take up to 4 hours to digest, where WPI takes an hour or less. The whole reason WPI was developed was to increase speed of absorption rates. Whey Protein Hydroylsate is faster again with a higher concentration of di, tri & oligo peptides.
Lol. I did. I know better now.Fark Sherk used to get emotional about protein!
I've got iron guts, WPC all the whey (see what I did there??)