I can hear a slight octave up , but in a dirty brass master style. Ive used many different octaves over the years and as I prefer to use an octave as part of a synth engine the T65 is perfect for me. It can even be used on its own to good effect with the octave up for synth duties.
I do agree that the T65 doesn't do completely clean in the same way I found the T16 could, that's why I'm considering a custom Cog, which would be switchable between a T65 and T16 (kind of a T47 with a loop and one channel having the octave up).
For clean octave tones, my favourite is the EBS Octabass! Clean smooth sound that tracks really well. I'd buy Oldman s but I've no room on the board!