I have a LOT of old slides and negatives, and some photos for which the negatives have been lost, and I wanted to digitize all of this. I looked at what was available and read a ton of product reviews and there seemed to be a choice of either cheapie low quality "toys" with poor resolution, or else professional -oriented products at upwards of $1000. And then I saw the Epson V550 and V600. Priced in the lower-middle of this range, they advertise as good a scanning resolution as all but one very expensive product. I checked these out and found that the V550 is the same machine as the V600 --they differ only in that more photo processing software is included with the 600. SInce I already have a photo post-processing app, this didn't matter and I went with the 550. I got lucky ---it was on sale, AND I had a Best Buy percentage-off coupon for which --amazingly-- this product actually *wasn't* on the (always hideously long) list of exclusions!!
But I still had to check out the important thing -- did it really work as claimed? I tested it with some 35MM slides first; it took me a minute to figure out how to insert the slide attachment tray, the instructions for the scanner really could have been written better --but I figured it out, and then tried a few scans. Went thru different resolution settings, etc, and found that at 600DPI or above, it does a pretty good job!! 1200dpi seems best for slides, but the scanning process was VERY slow...so I did most of them at 600, and really couldn't see a difference except when the photo was "blown up" to full screen. Color reproduction was good; there is a "color restorer" function in the V550 software, but since I have another photo app I prefer to use, I did not use it. The included slide scanning attachment holds 4 slides at a time; given the size of the scanner, I felt they could have designed it to do more than 4, but it was really no big deal since each individual slide takes a fixed amount of time to scan which depends only on the dpi resolution setting you use.
Next I tried 35MM negatives. The attachment tray for these holds 2 strips (of up to 5 or 6 exposures each). It has a snap-in "frame" that is supposed to hold the negatives flat for scanning, even if they have become curled; in fact it did a pretty fair job with this, if not absolutely perfect. It is just a bit "fiddly" to place the strips of negatives into the tray, but again, it wasn't a big deal. Once again, I ended up using 600dpi resolution for many of them, going up to 1200 for only a few particular pictures that had a lot of detail or ones I especially intend to make big prints of..
Overall, it is a good product and if you find a sale, it is a real bargain for what you get! --and it will also do all the "usual" scanning stuff such as documents, too, since it is a full size unit.
On the "con" side, it is rather large and bulky, and the instructions really could have been written better ---but I found there are reviews by serious photo enthusiasts which included useful setup information!
It is very slow if used at high resolution --but it will do a good job for those photos you really want to preserve as well as possible.
Also, especially with transparencies, you must be careful to keep both the scanner and your slides/negatives clean. I kept a can of that pressurized air spray stuff handy; otherwise every tiny speck of dust will appear as hairs and spots on the scanned photo. As far as I know, this is a problem regardless of which product you buy, so the Epson is probably no worse than any other here. (There is a dust removing feature in the software, but of course any app like this will have *some* effect on your photo content; it is better to just keep really careful with cleaning!)
To sum up --this scanner is a good value for the money!