It has been stated here previously by Terry and others in numerous threads that the performance of the Ultramax and Drake is very comparable. So it boils down to your preference as far as looks: one-piece (Ultramax) or two-piece (Drake). I personally find the one-piece models more attractive and there's no gap between tank and bowl for liquids, bacteria, mold, etc., to collect. Then there's the price difference to consider because the two-piece models are less expensive.
The Ultramax also includes the premium seat whereas a seat for the Drake must be purchased separately.
Nothing abrasive should be used on CEFIONTECT. You should be fine with any liquid cleaner as long as it's not acid-based.