End-quality centers around price, generally. I use an Epson Perfection 4990 and Silverfast AI software. The current generation of that scanner is the
V700 (which actually is a step up).
The 4990 is a 4800dpi scanner, the v700 is 6400dpi - I don't know what Basil's is. Optical resolution is what to look for - IMHO "interpolated" resolution isn't worth considering. For archiving I start at 3200dpi for 35mm size images.
A friend of mine tried the $100-level slide scanners and found them to be really good paperweights.
A couple of things to look for and be aware of: a good film/slide scanner should have some variety of "digital ICE". That system uses an IR scanning pass to identify film defects and dust, then automatically removes them from the image. It isn't perfect but it works really well...unfortunately it won't work with Kodakchrome or B&W silver-based film (you can scan the base-side of the film instead of the emulsion-side and sort of make it work "sort of").
The software makes a difference too, sort of. Silverfast makes scanner-specific software that can cost quite a bit but the overall capabilities far exceed the basic software that comes with the scanners. They have versions that will do multiple passes to pull more detail from the film, and options that will effectively add their version of digital "ICE" (using the IR scan) to correct defects even on Kodachrome. If you're doing a lifetime of film scanning for archiving the extra price <span style="font-style: italic">may</span> be worth it.
Here are some samples of different types of material from the 4990-
From a 6x4.5cm B&W negative:
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35mm B&W negative:
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35mm Kodachrome Slide
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Ektachrome Slide from the 50s
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35mm color negative from 1992
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