Agree with Hank - I think the chucks themselves are identical. The difference is in the accessory jaws. Both sets include the #1 and2 jaw sets. The c kit includes pin jaws and the larger #3 jaw set (for larger bowls), while the se kit includes pen jaws.
I have the Baraccuda chuck (with tommy bars). In my opinion, the most useful jaw sets are the longer 'alligator' jaws that aren't included in any of the sets. But my choice between the C and SE sets would be the C set - I don't see any particular need for pen jaws. They are intended for holding pen blanks with square or rectangular cross sections for drilling. I prefer to turn blanks to round and cut a tenon that I can then grip in standard jaws. Just the way I work - your mileage my differ.
