Michael.......
Because you like one shape, and your wife likes another, it should give you an indication that you can't please everyone. The best advice I could give, is to do what you like mostly, with an occasional calabash for your wife.....but, you may have to distinguish between her desire to have something that is personal for you, given to her......or, something only she wants. There is no right/wrong good/bad in that, just that you have to set priorities for yourself, without letting anyone else influence that. I subscribe to this philosophy and have been doing what I like since day one.
Since I intend to sell my work, the rules change a bit, but the basic concept hasn't. You will find there is a full spectrum of those who buy turned art and bowls. The great majority of the buying public are budget minded, and there are a ton of turners who service that market......mostly resulting in plain works that don't have much of anything that really distinguishes them from the others.
I find that my works are being purchased by those who have disposable income, but only those who like what I like! ......So, my basic philosophy has still not changed.....I'm still doing what I like, and not compromising my personal artistic reach to make a sale.
I'm drifting from the main subject some.......sorry. I do want to make the point that you are more in tune with an artistic level of appreciation, with your preference of the "hour glass" shape, while your wife has more of a utilitarian appreciation.......in my opinion, of course!
-----odie-----