If you are using Th.M. as "personal enrichment" and would eventually work on a Ph.D. I would then definitely recommend WTS-Philly. Like I said you are practically sitting in Ph.D. courses and expected to turn in Ph.D. level work, but at half the load of Ph.D. instead of the full load. Needless to say the programs are very "enrichment" and will prepare you for your Ph.D. journey (anywhere after that.)

If you are thinking of Apologetics I can't think of anywhere else better (at least for the Van Tilian Reformed Apologetics), if you are thinking of Church History again I can't think of anyone else better to study under in Carl Trueman and his trusted collegue Jeff Jue. As for ST Lane Tipton is relatively young and less known in the academic circle but having taken a few courses with him I don't think I'm exaggerating when I say he has the potential to be a big player in the theological circles given a few years. And yes WTS ST department will attract major theologians to teach in Sinclair Ferguson, Daryl Hart, and others.

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Reverend David Chen
Faith Hope Love Chinese Church
Havertown, PA