yup u are right that my canister outlet goes into my chiller inlet and no separate pump is required. This is better as the canister helps to filter the water and prevent larger debris from entering the chiller which will eventually clog up the chiller.
of course with higher head, ur flowrate will be slower, so do make sure that your canister have a high head. eheim 2026 have a max head of 2 metres.
disadvantage :
i am a very lazy person. i dun like to clean canister. and even with the pro 2 series , i still find cleaning a hassle. but if u allow the canister to build up, ur nitrate will increase significantly. clean at least once a month. =)