It was the low-end member of the Amiga range for a while, so I suppose it was "the worst Amiga model that you can buy" new at that time. The same could have been said of the A500, A500+, A1200, etc. at other times.
But certainly a decent machine. The worst Amiga in terms of capabilities would be the A1000. In terms of price/performance, I would propose the A2000: an extra thousand or two dollars (compared to A500) basically just for a few card slots.
Why did the A2000 cost so much more than everything else? I have always wondered about this because as you said it offers nothing more than a few extra slots...
I'm guessing it's because chickenhead was trying to make a profit so they marked up the price? Or maybe the A2000 price was right but the wedgies were under priced? Maybe it is because of the better PSU?