Soft Black Pencils - the search for a Prismacolor alternative

If you've watched any drawing tutorials or car design sketchers on youtube you'll probably have heard about black Prismacolor pencils. I tried some a year or so ago and was delighted with the smooth waxyness, the lack of sheen, and the rich tones I could get with them - but here in the UK they weren't easy to find. You need to resort to mail order from places like http://www.1buy1pencils.co.uk. Sometimes these suppliers run out of stock and I've read that the pencil quality dropped off a bit after they moved to a different manufacturer. So what options are there for UK sketchers who like soft black pencils? Are there any others as good as the Prismacolor? I ordered a selection (mostly from http://www.pencils4artists.co.uk) and tried to find out…

PRISMACOLOR 935 - not too hard, not too soft, not too waxy, not too dry. Smudgeproof. Just about perfect!
CARAN d'ACHE Luminance 6901 - a tiny bit less waxy than the Prismacolor but gives an almost identical range of tones.
CRETACOLOR Nero Soft - Much drier - more like a graphite pencil but still gives deep blacks with little pressure. Hardness will probably mean it keeps its point well. It's a slightly warm black and does smudge a little.
FABER CASTELL Pitt Oil Base Soft - A little less waxy and a tiny bit lighter but very close to the Prismacolor.
LYRA Rembrandt Polycolor - Slightly slimmer than the others which - I find very comfortable. A little less waxy than the Prismacolor and it doesn't give such rich blacks.
DERWENT Coloursoft C650 - Less waxy than the Prismacolor but still gives a good range of tones. Again a slightly warm brownish black.
LYRA Color Giant 3940099 & Super Ferby - Chunky pencils. Too hard and slightly brown. It's a shame that companies mess around with the formulas. I have a stub of the old 9305 Color Giant which is every bit as good as the Prismacolor - perhaps even better - with rich, pure blacks  and great softness. Ho hum.
STABILO Trio - Chunky and triangular. Available from Staples office supplies. Very similar range and feel to Prismacolor but ever so slightly warmer.

And a couple of others that are a bit more extreme than the Prismacolor…
STAEDTLER Lumocolor - Permanent and waterproof. It's incredibly soft and waxy - almost like a wax crayon or Chinagraph but lovely and smooth. Could be great for large gestural sketches or even sketching in the rain! Be prepared for lots of sharpening though. Bit of sheen and does smudge a little.
CONTÉ Pierre Noire 2B - a sort of Conté crayon in pencil form. Dry like charcoal rather than waxy. Lovely sooty blacks, completely matt. As you'd expect, it does smudge.

CONCLUSION: If you find yourself out in the wilds without a Prismacolor and there's an art store nearby you might find the Caran d'Ache or Faber Castell makes an excellent replacement. The Cretacolor, Derwent and Stabilo are very close seconds and all very nice to draw with.

Although the Staedtler Lumocolor and Conté don't fit into the wax pencil category they are still definitely worth a look as they make some lovely marks.

Lastly, I ought to mention my new KUM automatic long point sharpener. It's a two-stage sharpener which sharpens first the wood, then the lead, and it's done a grand job of sharpening all of the above pencils (except the chunky ones) - even the very soft and brittle ones which my old sharpener used to snap the leads in. It might be down to new blades but I think sharpening the wood first is a good idea as you can then go very delicately when you come to the lead itself. My model also has a couple of small holes in the sides for sharpening clutch pencil leads (2mm and 3mm I think)

Hope that helps! Let me know your thoughts.