Not a fair comparison. The 8500 is an all-mode receiver capable of HF thru X Ghz.
The Alinco will probably have a better front-end for HF as most wide-band receivers sacrifice that for the wider range. I don't have any first-hand experience with the 8500 so it may not suffer much here.
The 8500 is surprisingly good on HF. That radio really is two radios in one box, an HF rig and a 30 MHz and up rig, with separate front ends to a great extent.
I have never compared the 8500 to the R8 because I never had them side by side. I have done a “light” comparison of the R75 and R8 side by side. In general I found the R75 to come out on top.
I have also done extensive testing of the 8500 beside the R75, I have two of each here at the listening desk. In general the R8500 is not quite as good on HF as the R75, but the difference is so very small, for practical purposes I call it a wash.
I agree, not a fair comparison, the R8500 brings so much to the table, the R8 doesn’t have a chance. Unless of course you do not need the extended coverage of the R8500, and then the question must be asked, why even bother to look at it? The R75 is much more in line with the R8, and in my opinion the R75 is the better of the two.
As Martin pointed out, the cost is the big factor.
Also, the I/Q output from the R8 is a pretty cool feature. It's essentially a receiver and SDR in one box.
The R8 is more of an SDR
or traditional receiver, not both at the same time. When you select the SDR output (very narrow banded by SDR standards, 24 kHz) the traditional output cannot be used. So you cannot, for example, listen to the audio from the radio while watching the spectrum at the same time.
At least that was the way it worked when I tried one, not looked recently to see if they have changed it.
Also, the control software for the SDR of the R8 left a LOT to be desired.
T!