Kintting

That's an interesting question.  And it depends on the style of sweater.  And how much time you want to spend on it.  Some machine made sweaters use very thin yarn and thin 'needles', creating a very tight, clean looking sweater.  This would take even the quickest knitter very long to make.

 It is true that a machine will rarely make mistakes.  But so do very experienced knitters.  With enough practice, stitches can be made very even.  And the hand knit sweater would be more expensive (if you include time of production and materials).  But creating a hand made, one of a kind sweater is invaluable.  

 All in all, I think a hand knit sweater can be made of very high quality (with experience and knowledge (and a lot of time)), and the experience and product are well worth the extra effort. 

It is entirely possible, and indeed very probable, that an experienced knitter will create a sweater that exceeds the quality of anything mass-produced in terms of style, fit, comfort, and suitability.

It sounds as if your wife may be a beginning knitter, but she can't become an experienced knitter without starting somewhere. While I do not knit, I know many people who do (including my daughter), and I have seen some beautiful things produced by people who have just learned to knit.

I would take the fact that she wants to create something for you as a compliment and a sign of love. If the sweater doesn't turn out well, she'll probably judge it far more harshly than anyone else, if she's anything like any other crafter I've ever known. I seriously doubt that you'll find yourself being expected to wear some poorly made thing that you'd find uncomfortable.

So, let her make you the sweater, she will be so happy to acomplish something for her husband. I knitt 2 for my lover, he was incredible happy, not only because I knitted for him, but because no one have something similar. And yes, by hand you can come very close to a mass produced, oh well!