The 100z2 was made in Y2k and is the bottom of the totem pole of RF amps. Don't expect to run a pair of 12's off of it or have it blow your doors off in volume. It's an OK amp. They're built well and sound good, just not very powerful. It's a shame they used those end caps as it could have been a pretty tiny amp for trick installs. The Punch 100z2 sold for $99 back in the day.Since you seem to know a lot about these older amps, what do you have to say about the 100z2? Someone's selling one in nice condition for $40 on my local Craigslist as well. There seems to be a lot of older RF amps for sale lately.
If it came between owning a Punch 40 or 100z2; buy the Punch 40.