Digital BW, The Print

Sorry my first reply was superficial.
  
The hypothesis that was put forward about product tolerances seems
plausible.   Or is the main issue are there some printers that are
just not going to work with spongeless due to prior history, as Paul
suggests?
Even with all the recent posts it is hard to tell.  It would be great
to hear from those whose problems had been fixed by changing to a new
cartridge. That would encourage those who are having problems. 

I've had good results from the spongeless carts in two 1270 printers.
One was previously used with dyes, one last used with UT-FSN/EBONI
CIS. The CIS progressively failed with irrecoverable nozzles "colour"
by "colour" - none of the tricks worked, and even new CIS cartridge
made no difference.  The printer was perfect on dye inks.  The
spongeless cartridges (UT-FSN) have been perfect (just very occasional
cleans needed), also those in the other 1270 (GP inks), except for one
leak due to a - I think - not well sealed bung (tape over it cured the
problem).  I have more problems with a 1290 with eboni/perpetual
archival CIS (foam every few months requires to be removed). 

One little thing I found (which could be troublesome) is that the
mounting of the chips is not very clever, it took a few attempts to
get a printer to accept a cartridge because the yellow plastic carrier
was 1mm out of position - I then aligned it with reference to a
genuine cartridge using calipers, and all was well.

Ken