Output-wise, I am more than happy with my V500. In the wider scheme of things it is relatively inexpensive and flexible, allowing me to scan MF as well as 35mm. If I require a better quality scan I will pay for an image to be professionally scanned.
My bigger bugbear is with quality control. My first V500 arrived with a faulty power supply and was returned to the store. The replacement (which I got from eBay) has an intermittent fault by which it will sometimes begin to scan when I click 'preview', but will then suddenly display a message that the computer cannot communicate properly with the scanner. I've tried a different USB cable, and firmly seating the cables at the back of the scanner, but to no avail. The curious thing about this fault is that when it manifests, I can restart the scanner and get it to work fine in full auto mode, but to try to scan in any other mode (including, most annoyingly, professional mode) simply results in the same error message and a refusal to scan, so the fault only manifests in certain modes. I've tried reinstalling the Epson software, again to no avail. Overall I am happy with the V500 scan quality, but do find its intermittent quirks rather frustrating.