The stirrer on my KR1220 is a HM-190M and it works just fine. The stirrer on the KR3020 is much bigger and I'm not sure what model it is. The only thing I'm looking at doing is getting a 'cross-hair' stirbar to replace the standard 'straight bar' style, as they are suppose to stir even better. I currently run the stirrer for 3mins, 5 times a day and it's doing the job so far.
I own 4 things by Barr Aquatics and I haven't seen anything yet that compares to the quality. (My Custom 62g Sump, Kalk Reactor KR1220, Protein Skimmer SK1620 w/ Waste Collector WC220) His products are definately worth the wait and price.
I like many, are not the DIY type. The plumbing on my Aquarium was enough of a challange, and there wasn't even that much to do. So I definately don't mind paying alittle extra for a 'pro' to do it for me.