My next loco scheduled to be fitted with supercaps is a heavy Bachmann N. The last time I ran this up against the buffers, the rails underneath shot out from the flexi-track with considerable velocity! With supercaps fitted the N will need to be driven very gently in the yard!
Let me say that I have no experience of DCC. One clear disadvantage of supercaps with DC control is that precise shunting, especially to auto-couple or -uncouple, is difficult and takes practice. I suspect that there is more control with DCC except when there is no track signal e.g. on an electrically dead section of track.
I have an aversion to investing large amounts of money in DCC; I think the future lies in radio control. My current strategy is to install supercaps in tender locos at low cost and to try R/C in small tank locos so shunting will be less of an issue. Just think about the wiring. The next layout may have lots of dead frogs!