Hi videobruce,
While I do not own the 51HX93, I am strongly considering it or the 51HX83 model.
Either is great, bu the 93 model gets you the builtin tuners as you know and fire wire ports.
If you can use the built-in tuners to pull in HDTV programming, I would say go for it, just make sure it is not encoded which would require a STB. I live south of Toronto and according to my cable company I would have to get one of their STBs to watch HDTV because their signal is encoded, and I don't have the luxury of OTA HDTV transmissions.
Do you know of any OTA programming in the Buffalo area?
One last thing, you can download the user manuals from the Toshiba site and scan through them. The HX93 model is not listed yet but the H93 is.