I have been checking here periodically looking for updates to the late, neglected DC v4... I guess this is the answer!
How would a DoubleCAD devotee procure a copy of said TurboCAD LTE Pro v5?
Home-Dell T3400 Quad Core Q6600 OC'd 3 GHz., 8 GB RAM, Radeon HD 3870, Windows 7 x64
ACAD 2012, DoubleCAD XT Pro v3, Alibre 2012 Expert, 123D