It is very important to remember that the results from any equipment are often largely constrained by the operator. This holds true for cameras, guitars, scanners, etc. If you have better scanning skills than the folks at ASDA, then you could possibly overcome the technical limitations of the Epson to generate better scans.
Personally, I only consider Epson scanners useable for black and white negatives, although I cannot rule out operator error as a primary cause of my dissatisfaction with colour scans.