Reading in a Cook's Illustrated 2003 about the performance differences
between both KitchenAid handheld and standing, they did side-by-side tests
on whipped cream, egg whites for meringue, cookies, cakes and butter cream
frosting.

"Our conclusion: The standing mixer offers greater flexibility and
versatility. (It's dough hook is ideal for kneading bread, something a
hand-held mixer can't do.) ...
We found however, that with some adjustments for time and technique, the
hand-held mixer generally yheilds baked goods that are identical to those
prepared in a standing mixer."

There were other comments. p. 24 Nov.& Dec. 2003 issue.
Dee Dee