Hi Victor
I had also favored the TC but ended up buying the ALPA SWA last may, and a P45+.
The extra wakeup grip for the TC works fine but you do loose the great advantage of having the most compact and simple camera possible with a MFDB anyway.
You should seriously consider the WA or SWA with the wake-up grip (on the left), trigger and cables for Phase One, as it's the best integrated solution there is for the wake-up signal required. You very quickly get accustomed to first press with the left forefinger and then the right (within 4 sec) to release the shutter.
And handholding a SWA is a real joy, feels extremely solid and provides a stable platform even to do some handheld shooting. I prefer it to the TC.
Obviously for best IQ I use a tripod.
regards, Jost