What's a "strong" signal (airport)

I'm using an Airport Extreme base with an Airport Express downstairs to extend the range. I get all 4 bars on the Airport meter at the top of the screen.

For grins, I downloaded a few widgets that have signal meters -- they indicate 40-55% on their scales.

Which led to my question -- what is considered a "strong" signal? I would have thought that with my configuration I would have been 90% or better (the Express is only a few feet from the iMac downstairs, and this is a "standard" 2 story house -- no metal/brick walls, etc.).

I've never been impressed with Apple's wireless products although they sure are a snap to configure. I still use an Express here in my study but I've changed out the Expreme Base for a Netgear Mimo wireless router and... wow, what a difference! Also, if I am outside with my laptop and have only a bar or two my machine is still fairly responsive, though it does load a bit more slowly.

So,...you put 100% percent faith in a widget? That's like saying everything on the internet is true!

No -- I've run several different tests, but nowhere does anyone ever seem to say what exactly a "strong" signal means. We've all been well trained to think "bars" is enough.

But, clearly, no one here seems to know either.

No big deal, just curious.

I went through a similar thing-- I used iStumbler and noticed my wireless network usually reports in the 60-75 range, for whatever that's worth. I found that for me, that was a "good" signal.

I decided that as long as I was getting decent throughput and I have 3 or 4 bars, I'm good to go.