KA killed its reputation with those infamous plastic gears and housings when they separated from Hobart. However, those problems were resolved some time ago when they switched back to metal (at least for the 5qt "Commercial" and 6qt "Professionals"). I'm pretty sure the KA warranty goes for a year on the gears and housings, you have to check. Unfortunately for KA, it's not only the stench which lingers, people still downgrade them on the basis of plastic which is no longer there. At any rate if you're worried about plastic, don't be. Not the heavy duty workhorse that old KA/Hobarts once were, but a new Commercial might be the best choice for you.
If you're wondering whether the 5qt Hobart is better than the KA Commercial clone... Yes, it's quite a bit stronger. It also costs four times more. Price being in issue, there are probably better choices for you.
You can certainly get more heavy-duty counter top mixers than the KA Commercial from Vollrath, Axis, Globe, Hobart etc., but they cost two to four times as much.
You might also look into the possibility of buying an Electrolux stand mixer (aka Magic Mill, aka Verona/Magic Mill DLX). They're belt drive, very steady on the counter, and last forever. The "dough bowl" is 8 qts. The "whisk bowl" is 6 qts, and since the beaters come from below, you don't have to work around a drive arm when adding stuff. I'm not sure if they're NSF rated though. If it is, everything considered it's probably ideal for your purposes. ~$700.
BDL
PS. Forgive me for poking my non-pastry chef nose into this thread, but I do know a bit about counter top mixers.