Sometimes old tech is still better...

[Ilwrath]

I think you can buy much better scanner today than MicroTek for its old price.
this reminds me of old LCD vs CRT debate. every technology has its disadvantages.

For sure...  And, honestly, I wonder how much better scan you'd get from the HP with a decent driver.  Maybe try it under Linux, if it's supported by SANE.  Most of the image issues sound like a combination of the image getting automatically jpeg compressed, and then color corrected and sharpened.  It wouldn't surprise me if the scan software was bad enough to jpeg an image internally before exporting as a TIFF.  

There are few things more infuriating than HP's drivers.  They do all sorts of unexpected things "automatically."  As mentioned above, just installing them usually gives you a host of adware, demo software, and updaters.  And the drivers, themselves, aren't any more open about what they're doing once they're installed, either.

[Ilwrath]

I even turned off all software sharpening in the scanner software.

That HP driver is obviously not honoring your request to not adulterate those images.  Don't believe me? Just take the e3s image one and apply a 2px sharpen.  (And a harsh one at that.  Maybe 75%.) Take image 2 and apply a standard color correction.

The hardware isn't the problem, per se.  Its those terrible drivers and software.  Unless the multi function device is automatically applying these filters before it hands the scan to the os.  This may be the case for devices that can scan directly to email or smb share.

I've never been fond of software that thinks it knows better than me what I want.  And in that respect the old ways were better... But I really don't think you can blame the optics or hardware in this case.

[Ilwrath]

Yeah, I tend to agree with you after staring at the images.  The white outline looks like the effects of oversharpening (unsharp mask) and increased contrast.

Indeed.  Exactly like it.

Interesting that the HP 3-in-one couldn't pick up the subtle blue shades (it does the same with light pink or beige) but this might be a result of a contrast boost filter being applied automatically.

No, it's the auto-color correction.  It picked up the blue tint just fine.  Then it incorrectly auto-corrected it to white.  That's why your greens look brighter, and your red path went wacky.  The image got corrected against a "blue light" condition, which messed with the color balancing of the entire image.

Not sure how I'd fix any of this other than to buy something like VueScan, which is commercial software.  Not really interesting in paying more money to fix something in the HP 3-in-1 that shouldn't have been broken in the first place, when the ScanMaker E3 works fine.

Very true, there.  If there's no free alternative that supports that scanner, you're screwed.  But, of course, you could still pick up a $30 scanner that is supported under free alternatives.  The lesson isn't necessarily that older is better, but open, free software is often better.  Especially when on a budget.