THINGS TO KEEP IN MIND WHEN WORKING WITH THE PROFESSIONAL
--Always grip the handle, not the shank.
This insures that when you push on the handle, the result is a pure turning force on the pin.
--Always carry an L-lever.
While the Professional fits onto virtually every pin on every grand, there are exceptions, such as the last few bass pins on Yamaha grands and pins close to the capo in the high treble of large grands with wide plate webbing. You'll need to use a conventional L-lever to reach those pins.
When you're tuning a vertical with a large overhanging lid, you may prefer to use a an L-lever rather than leaning the lid against a wall or removing it entirely in order to make room for the Professional.
In addition, you'll find it useful to have a small, lightweight conventional hammer for pitch adjusting (when you want to move rapidly from pin to pin) and for those non-tuning jobs for which L-levers are so handy: making string repairs, adjusting glides, seating strings, spacing grand jacks, releasing vertical action brackets, etc.
For all those reasons, you should always carry an L-lever when using the Professional in the field (the Utility makes an ideal companion).