i have several AC110's i use as backups and what not, plus one thats been running nonstop for several years, and is on a bichir tank now. there quite well made it seems, work perfectly, and you can customize the media however you see fit.
i run mine with one foam and the rest stuffed to the top with bio-max. ive also used it with 2foams as nothing but a mechanical beast, and it works wonderfully.