Robbie Rhodes has summarized the issues of roll perforating very well.
In short, the actual perforating is a small part of the whole process.
Laser cutting is a neat idea at first glance, but doesn't make economic
sense.

When I decided to build a perforator I considered many ways to make
holes in paper.  My brother and I (he is the machinist of the team and
a very practical minded guy) kicked around all sorts of ideas, including
a laser, water jet, air jet, air or fluid operated cylinders for each
punch, solenoid direct operated punches, and others I don't recall at
the moment.  The appeal of the laser and jet approaches is the ability
to change format with software, rather than some mechanical approach.
The laser and jets also gave promise of much faster throughput.

We eventually settled on the traditional gang-punch and interposer
form, for several reasons:

1.  At the target punch rate of 30 per second, and an advance rate of
240 steps per foot ( 0.05 inches per step) this would punch 8 copies
at 7.5 feet per minute, or 8 copies of a 30 foot roll in 4 minutes.
A stepper drive with resolution of 0.002" allows any advance pattern
with an error of in the order of 0.001", closer than original rolls
were made.  Processing a roll after perforation takes perhaps 1-2
minutes each, with a proper production setup.  So we're looking at
a post perforation time of about 15 minutes to process the rolls that
took 4 minutes to punch.  Even a 60 foot roll would require only 8
minutes to perforate.

2.  Cost.  This is the least costly system to build.

3.  Development.  The gang-punch system has been used for over 100
years, and the technology is well tried.  Any other approach would
require breaking new ground, with the good possibility that there
would be difficult problems to resolve.

4.  Maintenance.  With the possible exception of the laser, the
gang-punch is the easiest and least costly to maintain and service.

We had the advantage of starting out with a clean sheet of paper with
our design.  With the invaluable help of the Tonnesens, we designed
a system that built on their experience with their perforator, and
improved some of the features.  One of the things we did was to design
the ram and die assembly for (relatively!) quick change to a different
set.  This made change of format about a 4 hour job, about half of
which is removing and replacing 100 interposer pull wires.  So we have
largely gotten around the advantage of the laser, etc. approaches to
format change.

This leaves us with throughput the only advantage of a laser system,
which can't be put to use unless we are talking about an operation with
many people and a large market for the product.

Right now we are operating at about 15 perfs/second, and using the
Tonnesen's PRF file format, which runs at 540 steps/foot.  This means
we take about 18 minutes to make a run of 30-foot rolls.  This is fast
enough for the de-bugging phase we are in now.  Even at that perforator
rate it would take about 15 minutes to process the rolls after
perforating.

I was tempted by all the whiz-bang new technology, but the old
tried-and-true approach made the most sense.

Bob Billings