Okay, so I finally bought it. I had a 135 slide, a 120 slide and a 135 B&W negative still unpublished and plan on shooting more analogue so I decided to get it. I bought it over the internet from a nice Austrian company called IK-Cabling who don't have such a good online shop, but good customer service.
The size of the V500 is reasonable for an A4 scanner, it's not too heavy and does feel a bit cheap because of that. The look is nice and the black colour should make it fit almost anywhere.
Scanning is quite easy, you take the loader for 135film and put in the negative or slide stripes or if you've got the slides framed you can put them in as well (up to 4 at a time). The loader has markers on where to place it. Then you scan a preview and the software automatically detects the individual images. No rotating or cropping necessary. This is really convenient. The loader for 120 film isn't as convincing though, it's designed for 6x12 so theoretically you could fit two 6x6 (which is what I use). Practically it didn't work to fully get both pictures on it. The loading also requires a bit of fumbling and isn't as smooth as with the 135 loader. But thankfully 120 film just has 12 pictures and not 36 :-)
About scan quality: As expected. It doesn't seem to come near to one of the professional scanners, but I think it's good enough for the price. There's quite a bit of colour noise in the scans, but this also depends on film speed. It was a bigger problem with a 135 Sensia 400 slide film and less so with a 120 Velvia 100 slide. It's also more severe the darker a photo is. Nevertheless a simple colour noise reduction in Photoshop and the problem is gone for well lit photos and mitigated largly for dark photos. I also scanned an expired 135 Ilford HP5 400 where I also had 10x15cm prints (matt, not mirror-finish) done in a professional lab. At first I was shocked about the amount of noise (grain) in the film when scanned from the negatives. That's a lot worse than ISO 3200 on my Nikon D80! So I tried to scan from the prints, but these turned out quite soft in comparison and I stayed with the negatives.
I scan 135 film at 2400dpi which results in ~7MP, for 6x6 I use 1200dpi and get ~6MP. Of course it's possible to scan with more dpi, but I don't know anymore why I thought I'd need a scanner with at least 4800dpi. The files just become huge there isn't really that much more detail it seems, but I haven't tested this thoroughly yet. I guess I'll have to compare them on a larger print.
Dust is of course a problem and the digital ICE automatic dust removal didn't really convince me (I just gave it short shot though). I use the healing tool mostly.
Overall conclusion after just two days of using: For 270€ (incl. VAT and shipping) it seems to do exactly the job that I bought it for.
Finally some pictures (reduced size only, I've got to upload some larger versions in the future), from a single roll of 135 Sensia 400 shot using a Canon EOS 500N with the 28-80mm kit lens:
I now also did some quick resolution tests. I took a medium format slide film that I had shot not long ago and put it into the scanner. You can view it here (marked in red is the area that the following crops are taken from):
It's scanned from a Fujifilm Velvia 100 that I exposed in a Pentacon Six with the Zeiss Flektogon 50mm f/4 (I don't know the actual aperture or exposure time anymore). I chose this one because I think I got the exposure quite well, although I took it hand held and it might not be the sharpest example. The sign in the following 100% crops measures about 4.6mm on the slide. The text that you can read well is 2mm long and 0.2mm high.
First here's a rather unimpressive 100% crop of a scan at 1200dpi, which I chose to be my default resolution for archiving.
Now the question is how much better does it get when we increase the resolution? So,I scanned the whole frame at 4800dpi resulting in a 10k by 10k pixel image which equals to a whooping 100 Megapixels! Saved in JPEG with highest quality it takes 52MB.
Click here for the 100% crop at 4800dpi (700x700px)
There's quite a bit more detail now and the text becomes readable better. It's a pity some of the text didn't come forward and is beyond the resolution of the scanner. Maybe a highly professional scanner could reveal the text, I don't know, but keep in mind that the height of the small text is less than 0.1mm in size. It's possible that this was already beyond the optical resolution of the lens. Nevertheless, I took it to the maximum resolution of 6400dpi (above is interpolated) and also 48bit colour depth. Because this would have probably taken ages to scan, I just selected the tiny portion that you can see here:
Click here for the 100% crop at 6400dpi (1200x1200px)
If I'd scan the whole 6x6 frame at this setting the resulting file would be 1GB in size and feature a resolution of 176 Megapixels.