both are great reps. TC YM is out of the box a fantastic rep, it is probably a rep which will go into rep history (WM9). plus it comes with gen Swiss ETA.
BP SD is great value for the money, but it will need some mods. after the modding, it will be on the same level as the TC YM.
these are two completely different watches.... I have them both (well, the BP is under construction) and they are both keepers which will guide me through the next 20-30 years (yes, I will take care of them and have them serviced).
I would say the SD is much more casual while the YM is very dressy and special. the YM should be worn by someone dressing very classic otherwise it will look stupid. I would even go that far that it should only be worn by people aged 40+ keep in mind that the YM was built to be a luxury Sub. I hardly wear my YM on the job (I am a lawyer) with a suit as I fear it might distract clients as it is so fancy. SD is fine with everything.