Recommendation for high quality color portable scanner?

[Titus 9]

I understand that many users have recommended the Scansnap series for scanning documents. Just curious - are there any comparable alternatives that are extremely value for money? Here are my criteria:

 

- Duplex 

- MAX quality color scan (Most important!)

- Portable 

- Plus if it runs off batteries or USB cables

- Can take in different paper formats (e.g. 300gsm art card, fujifilm photo paper, small thermal paper receipt) and sizes (a4, b5) at the same time, without error/double feed problems 

- Speed is not an issue - it can take as long as it wants to. 

- preferably less than $300.

 

On a related note, I'm also curious to know about the scan quality of these scanners vis-à-vis heavy duty office MFC scanners or consumer flatbed scanners.

 

Looking forward to suggestions!

[gazumped 9,569]

Have a look at Doxie scanners.  Don't have one,  but they seem well liked.