The summarized/simple question: What makes one tuner better than another?

I'm in the market for a new receiver. We listen to a fair amount of radio in our house, both AM & FM. (I prefer to listen to the local AM radio broadcasts of sporting events while I watch it on TV because I happen to like the biased reporting you get from radio for the home teams - especially for football).

Anyway, before I found the forum section of this website, I sent in a question asking this and got a reply stating that the 2150 actually had a better tuner than the 1070, but they didn't explain why.

Can anyone please explain to this stereo newbie what makes one tuner better than another, and why the 2150 has a better tuner than the 1070 (and how much better is it)? Are there differences in tuners in relation to AM versus FM?

FYI, I live in a near suburb of downtown Chicago. I don't have cable, I get great TV reception just through my roof antenna. The roof antenna is TV only. My radio antenna is just the wires that hang off the back of my current receiver. I would think I should get great radio reception, but both AM & FM stink. I get better reception in my car. Which leads me to think it's my current receiver.

Any advice/guidance much appreciated. Thanks,

Joe

http://www.fanfare.com/fm-specs.html

here's what the fm numbers mean,i can't find the am specs. a radio shack dipole antenna($3) would improve fm reception.might even pick up 'the loop'.when i was up that way i preferred lazer 103 out of milwaukee.car reception has always been better for me.

joe