dont know if there's a brand more superior than others or not.
rusk or biscuits, both r equally heaty. must let them drink lots of water after that. n dont give everyday.
i gave my boy heinz rusks (stick form, easier for him to hold) when he's 6months old. find that it's very hard. will need A LOT of saliva before the rusk will soften. takes very long to finish 1. so if your baby is very impatient type, he/she might get angry. mine did. so my husband had to bite off the ends which is extremely hard.
recently, i bought gerber graduates finger food biscuits. this 1 too soft. a bit of saliva, it'll break into small pieces. very messy. but my boy loves it. can finish 1 very fast n easily.
i personally prefer stick types than round ones 'cause easier for him to hold.