I'm sorry, I don't mean to insult anyone but this is crap. Recommending a blurry Epson flatbed to make 16x20's from 35mm is ridiculous, and so is comparing a DSLR to a drum scanner. It's just not reasonable, and I'm not buying it.
Lenny is right, and rightfully blunt about it.
I should have clarified that I don't think going larger than 16 inches with 120 film was from a drum scan. The comparison I made on my site between a wet-mounted flatbed and drum scan from a 2 1/4 was unsharpened, but trying to get an acceptable print from a Epson scan will take quite a lot of tonal massaging, careful sharpening, and modest print sizes with a good printer, paper, careful profiling, which is usually beyond what the average consumer the equipment is marketed for. That is why they have the preset unsharpmasking, and auto-exposure/tonal enhancements.
The reality is that most people are not going to go with all that is involved in acquiring/learning/maintaing drum scanners, so I would rather people learn the ins and outs of making good flatbeds scans, sharpening the carefully, and being realistic about the prints they can expect from them.
I never understood the fascination of making large prints from 35mm, traditional enlargements or inkjets. The film just doesn't hold the detail that will make a good print much larger than the sizes I mentioned.