I'll try to translate something from a book in Bosnian called "Svojstva Poslanikovog (saws) namaza" (Or: Characetistics of the Messenger's saws salah) by shaykh Safet Kuduzović. This is the best and most detailed book on salah I've ever read.
In short, there are two opinions among the 'ulama:
1. One should fold his hands (or her hands, as there's no difference between a man's and a woman's salah), based on the hadeeth mentioned above by sh. Ibn Baz, rahimahullah. They say these hadeeth are general and also apply in this situation. And they say: One who says that the one who performs the salah leaves his hands hanging has to come with a clear proof (Ash-Sharh Al-Mumti'a, 3/145-146). Also, they say: this is a state where the worhipper is more humble in fron of our Lord.
2. The second opinion is that leaving hands hanging is more correct because:
a. The ahadeeth which describe the Messenger's saws salah mention folding hands after the starting takbeer but don't mention folding hands after raising from rukoo'. If Allah's Messenger saws did fold his hands after rukoo' as well, that would have been mentioned, as its the case after the starting takbeer. However, that's not mentioned which means Muhammad saws didn't used to do that.
b. In the hadeeth where Abu Hurayra says that Muhammad saws tought that man praying, it's said that Rasool saws said that he should remain after rukoo' standing until every bone returns back to its place. And that can't be performed if you fold your hands.
Also, all four imams state this (See: Subulus-Salam, 1/393 with comments from shaykh Bassam)
As we can see, both groups have their evidence, and none has a 100% clear proof. Both opinions, understood from corresponding evidence, are correct, and we say what imam Ahmed said in a riwayah, and that is: both is permissible. (See: Al-Masa'il, 2/205/776 and Ash-Sharh al-Mumti'a, 3/146. It is known that sometimes imam Ahmed has more then one opinions on a certain mas'ala)
Wallahu a'lam, this is briefly translated from the book.
