Yes, it is a flatbed, but has a light in the lid for transmission scanning of film. It is *NOT* reflective film scanning. And yes, the 4490 is the one I have. And yes, it does a plenty good enough job for a web site. I usually send my neices and nephews pics at 4096x3072, which is 16 times 1024x768. It will do higher, but I can't email them, and more is totally worthless on a cell phone anyway. (Even that much is totally worthless on a cell phone, but I keep hoping they'll care.) As I said, I certainly don't think it's a professional solution. Think of it as like buying tools from Sears instead of a Snap-On truck.
I find the Kodachrome scans perfectly adequate. I think, although I don't really know, that this is because the OEM supplied scanning software doesn't have all the bells and whistles that get confused by Kodachrome. It just takes the image for you and plops in a jpg file.
I know you can buy other 'pro' software from third parties that work with it, but I never did this. My real interest is in the wet darkroom, and this was just an affordable way to get things 'electronic' for other family members who want it that way.