Marie,
  I've been thinking about some of the same issue you have.  My kids suggest
my thoughts are random, sort of like fizzly roman candles popping out of my
head.  Anyway, here goes...
  I deal with both pump companies, too.  Very little A. activity in my area.
I'm just beginning to see the new M. kits here, and I have only stocked dbl
pump adapters in new style because hospitals are providing new single kits.
Maybe this new design is intended to compete with Ameda kits which have
small, flexible tubing and dbl pumping with no Y-connection.
  Have got some thoughts on the PNS & its pricing.   I think the PNS is
intended to compete with the Double Up, which is Nurture III in fancy dress.
DU gets advertised in baby catalogs for $150, and PNS is only $50 more.  For
that mom gets the advantage of automatic pumping and suction adjustment,
among other things.  Thought it interesting that DU(NIII) has always had a 1
yr warranty, but PNS started out at 90 days, which was recently changed to 1 yr.
  Once M. sells a pump (to you or me, the rental stations), they get their
money & marketing the pump is now our problem so that we can recoup our
investment.  Sure, we're investing in flat rate every month, too, so M. gets
$$ no matter what.  The PNS allows M. to get a share of a developing
market--ownership of pumps by working moms.  (Linda Smith, I'm catching on
to a little marketing strategy, I think!)
[A random digression here.  Saw an article in a women's magazine a few
months ago.  A family having first child took a look at finances:  dad made
$45K, mom $32K.  Mom wanted to be home with baby girl, but they feared they
couldn't make it on one salary.  After analysis of expenses working outside
home vs being at home w/ baby, they discovered, much to their shock, that
mom netted only $7K of her $32K salary!!!  A few changes in lifestyle:
eating, entertainment, etc. made a big difference & they are living
"better"--their description--than before + putting money aside in savings.]
I think this is a market which the pump companies hope to tap into.  Upscale
families with both parents working, but mom wants baby to "have the best".
Gosh, this sounds so biased, but I grieve for babies & moms & dads.  We talk
about family values, but....???  I know these moms have to go the extra mile
to pump while on the job, take flack from co-workers & employers, etc., and
they are to be commended.  A major employer in my area is providing the PNS
to its bf moms as part of a maternity package--and, no, I'm not the rental
station involved!!
  Many of my clients (working moms) are very unsure of how bf is going to go
at all, saying, "I'm going to try to bf...."  We've all heard it a thousand
times.  Therefore they are sometimes hesitant to invest a couple of hundred
bucks in a purchase pump.  They prefer to rent for a month to see how it
goes, esp. if they got a kit via the hospital (back to insurance coverage
again).  Other clients, esp. those who must purchase a dbl kit at the time
of rental, and who want to bf for several months, are more likely to
purchase a PNS, thinking of it as an investment for future babies.  Time
will tell about how the PNS holds up over time & with multiple babies, but
I'm getting in positive reports so far.
Sara Reuning in Bristol, TN