A grand isn't an essential, but a good grand (modern, 6ft plus) is going to be much easier to play and get the best in terms of sound from.It sort of like motor cars. A 1960s Ford will work and get you from A to B, and so will a new Rolls Royce. Which is going to be the best to drive and to ride? No contest.That said, you will never get a first class result from an old, cheap, or worn out upright, or grand for that matter.I replaced my modern upright with an old (though good) grand, and that with a modern Yamaha C3. I can go to places on the C3 that would not have been possible on the upright (simply because of the tonal limitations of the upright). The C3 is also much more reliable in terms of its action than the old grand (inevitable because of improvements in design).I recently played a Steinway D (full concert) and was blown away by it. If I had a spare £80k, I'd have it tomorrow. But then there'd be nothing to look forward to
Oh how I would KILL for a Steinway D!! (...)
I have found that grands generally allow you to control dynamics much better by touch alone, without the need to go to the una corda pedal.
That strikes me as kinda perverse, given the una corda on a grand is more of a tonal than a dynamic device. On an upright its more of a device for screwing up the touch with almost no discernible effect on the sound.
Also I have yet to find an upright piano where the middle pedal works. Why do they even bother to include it? Or does it do something I'm unaware of?
My grand has a sostenuto, but I never use it. What is the point?