Rough-in and fit
Drake Transitional models are 12 inch rough-in as standard. Two Universal Height WASHLET+ models also offer a 10 inch option, sold as a separate model with .10 in the part number rather than as an adapter.
There is no 14 inch option on this range.
Adding a bidet
Several models in this range come as WASHLET+ sets with the bidet seat already fitted and the cord hidden behind the skirt. The bare toilets can also take a bidet seat later.
What makes it Transitional
Only the tank. TOTO pairs the standard Drake bowl with a tank that has gentler curves and a more classical silhouette, rather than the Drake's squared-off lines.
Everything that makes the Drake the workhorse of TOTO's range carries over: the same bowl, the same TORNADO FLUSH, the same parts availability.
Drake or Drake Transitional?
It is purely a styling decision. If your bathroom leans traditional the Transitional tank suits it better; if it leans modern, the standard Drake does. Performance is identical.