Sorry to mention but i should have pointed out that the PS3 was stuck in an update boot loop due to a broken bluetooth module. It was giving error 8002F1F9. So I'm guessing the press PS button is a sign of progress as it's not trying to update itself anymore.
When i flashed the original dump back to the PS3 it definately wasn't quick. Chip was not erased and it did behave in a way like you mentioned.
I cross-referenced the flash page with my dump and although I didn't go through all the addresses, the dump does in fact look like a good clean dump. But again just want to make sure of what I'm doing before I do any real damage.
On another note, I did try the 8Mhz Teensy Psgrade .hex file to see if I could get in Factory Service Mode but to no avail. Havn't pursued it any further so not sure what to do there. I left my Teensy the way it was (3.3v reg, 5v pad traces cut, 3v pads shorted) and plugged it into the rightmost USB port but it doesn't seem to jig the PS3 and continues to just boot to the "Press the PS Button"