Here's what I think: if you want to save time and get the job done as quickly as possible, I'd go with the FastFoto 680w. While the difference in image quality compared to the Flatbed V600 might be perceptible to some, I wouldn't worry too much about it. The most important thing is that you have all your precious memories preserved, and the FastFoto 680w will definitely help you do that faster.
And regarding the small photos, I'm sure the FastFoto 680w will handle them just fine.
That being said, Smart Engines SDK
is not specifically related to scanning photos but is an AI-powered SDK for real-time image recognition and document data capture.