and we mean a very few

The Akiles DuoMac 421 is a combination binding
system that offers medium volume users with three different binding
styles. Here is a list of what we consider to be some of the strengths
and weaknesses of the DuoMac 421.

Strengths:

1. All
   told, you can bind documents in three different styles with the DuoMac
   421. First of all, using the 4:1 pitch punch, you can make books that
   utilizing standard four to one pitch spiral coil. The 2:1 pitch punch
   function allows for the corresponding twin loop wire, and you can also
   use it to bind thick books if you use 0.400 pitch spiral coils.
2. On
   the four to one side, you'll find a thirteen inch throat with a
   strategically-placed five disengageable pins. Depending on which pins
   you choose to disengage, you will be able to bid documents that are the
   more common letter and legal sized, as well as A4, A5, and half letter
   sized documents.
3. The two to one side is fourteen inches in
   length, and gives you the ability to disengage whichever punching pins
   you choose, meaning that you can punch documents up to fourteen inches
   in length.
4. Both of the DuoMac 421's punches feature
   open-throated designs which means that using a fairly easy two step
   process, you can punch documents of just about any size. In order to do
   that, all you will have to do is to punch one side of your stack, then
   flip it over and punch the other.
5. Akiles saw fit to
   include a really high-quality wire closer on the front of the DuoMac
   421. With a lot of the other wire closers we have seen over the years,
   we've doubted their durability and have seen some of them start to lose
   accuracy over short periods of time. The high quality steel
   construction of these wire closers, however, left us impressed, and we
   see no reason why they shouldn't last a good many years.
6. Along
   those same lines, we have to say that we appreciated the fact that
   Akiles includes a pair of crimping pliers with the DuoMac 421. These
   pliers are essential to the process of spiral coils binding, and a
   thirty dollar value to boot, which is nothing to sneeze at.

Weaknesses:

1. 
   One thing that we missed having on the DuoMac 421 is a spiral coil
   inserter. Spinning your coils onto you document by hand is no bid deal
   if you are only doing a few (and we mean a very few), but if you are
   going to be producing any sort of volume at all, you will need to look
   for a standalone coil inserter. Akiles recommends that the Roll @ Coil
   be purchased to go along with the DuoMac 421. It's not a very expensive
   addition, but it is something that you should be aware of.
2. Because
   it includes so many features, inexperienced users may be a little
   intimidated by the look and operation of the DuoMac 421. It's got
   handles and levers and buttons all over the place and looks perhaps a
   little bit like a misplaced octopus. You really won't have much trouble
   figuring it out, though, just be aware that it will just take a little
   bit of a learning curve.