After checking reviews I have several questions:
1. A few people mentioned that it "walks on the counter" as it mixes and should not be left unattended. Was that the older model perhaps? Does it actually do that?
2. A couple reviewers mentioned that it was really good mixing a large amount of dough but wasn't very good at mixing small amounts. Is this true?
3. Also mentioned was that it is an amazing dough mixer but isn't that great for other things such as cookie dough and cakes. True? Apparently it doesn't clean the bowl very well while mixing because the beaters don't hug the bowl very well.
4. Could be hard to clean the shaft in the middle if the dough gets caught in it. True?

Any personal experiences would be appreciated.

The Kitchen Aid can only make 2 loaves of bread at a time; the Bosch can do 4. The KA has a hard time with whole grain doughs; the Bosch does not.

The Bosch occasionally "walks on the counter" if you are doing a large batch of heavy dough at high speed. But ordinarily there is no problem. Placing a damp folded tea towel under the machine can help prevent this, in any case.

I find that it is just fine at doing smaller batches of dough-- I make pizza dough in it frequently.

Actually, I think the beaters are better than the KA, though it is fine for cakes. But I find that the KA beater often doesn't catch dry ingredients on the bottom of the bowl. For cookie dough in the Bosch you need the cookie paddle.

As for the shaft in the middle of the bowl, if you are making a very wet dough, it can get into the center, but you can unscrew the shaft and clean it out.