the jackpot freerolls are ok, for ACR they are $250, which is nice, but the fields are much, much bigger than the ACR fields. Could be 800+ instead of 120-250. The "jackpot" that is advertised is probably nearly impossible to win, and doesn't seem available to ACR players anyway.
Most of these jackpot freerolls has a rebuy available and I would definitely not rebuy into the tournament. You first register and buyin of 1c then the rebuy is something like 20c which is just silly to me. Generally the field is large but it suits different players.
Good luck at tables