I would highly recommend the 91 deg. Much better for miter folding.

Pg 115 of our catalog

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I find that plywood I get is not flat enough to get good miter folds with. The PB and MDF core stuff works well with the insert cutter.

Well we're on the topic; are you guys cutting through the parts completely then taping and assembling, or are you taping then putting on the machine and folding as it comes off.

In response to Gary:
We cut to tape depth if we can, but if the parts are not rectangular, or the yield is terrible, we cut though and then tape off the machine. For anyone deciding on a machine, a V-groove saw with insert tooling is far superior to routing a mitre in a production scenario. We saw when we can, but still use a router bit when we can't. My advice is to add a fixed or servo controlled saw if you can. Aggregate heads are a step up, but not as rigid as a saw.

We tape off the machine. Just never tried the other way so can't say id one is better than the other.

we use a v-grooving aggregate. you need c-axis.

We miter folding all the time. Have made many boxes like you describe. You can use a CNC or an edge profile machine if you have one works better. We use 2" clear packing tape and tape it extensively. Also, you should cut a square piece the size of your inside opening and wrap the edges with tape to keep the glue from adhering to this piece. This piece will help to keep the box square. You should also cut hand holds into this piece so that you can pull it out when the corner joints have dried. The only time we use our CNC for this is when we are making tapered columns. Great fun, good luck.