Outstanding run through...far too many people just fundamentally misunderstand the functions of all the modules.
One thing I would add and emphasize...do *not* drive either piece until there is indicated limiting. They distort, guaranteed.
On the 8-band, when you initially configure it, there are two pots on the bottom, input and output gain and a jumper for mic impedance. It is important you set the jumper to match the mic you are using or it will drastically affect the sound quality and performance of the mic.
1) Work the mic at a consistent distance. Form your hand like you are going to do a karate chop, place it long ways at your mouth so that you set the distance to the mic at the width of your hand. This is a good generic distance you should be from your mouth to the direct center of the mic element.
2) Set your jumper to the correct impedance and enable the phantom power *only* if your mic requires it. If you have no output at all from your mic...it may need it, otherwise always leave phantom power off.
3) Flip the 8 bander on it's edge so you can see the top of it and reach the pots underneath it. While using a very loud, almost shouting voice, bark out 'five' 'five' 'five' and 'two' two two, emphasizing the punch on two. Bring the input gain up until you see the red light on the right side top of the 8-band lighting up. It is now clipping and will definitely distort your audio. From this point slowly bring the input gain down until you no longer light the red light AT ALL during any normal and even elevated voice level. If you yell, it will light, but no normal speech or laugh should even light it up a bit...this is very important.
4) Next is the output level pot, turn it all the way counterclockwise which is off. If you are driving a rig directly, put your rig into a dummy load and SSB, and flip the rig meter to the ALC mode. Set the mic gain on the rig to its sweet spot...where it normally would give you proper (2/3 to 3/4) ALC deflection on normal speech with a stock mic feeding it. Slowly bring the output level of the 8-band up, it will be a pretty fine line, until you see proper ALC deflection. With the EQ Plus as the next device in the chain, set its input level to around 10-12 o'clock and do the same watching it's meter. You want to see maybe two yellow bars, but no indication of clipping at all.
Either of these pieces, with the 8-band being worse, will distort if you overdrive them. Same goes for overdriving the mic circuit in your rig with too much output from your outboard equipment.
This is all referred to 'gain staging' your signal path. If you find that you are cutting the drive level in the middle of the chain, you are doing something wrong. No stage should come in hotter than it goes out. There should be even levels or a gradual progression from low at the input to highest at the output of the final stage.
The single biggest mistake people make with outboard gear is fouling up their gain staging and getting either lousy audio quality or a clipped and dirty signal on the band.
I also agree that the 8-band is the lesser of the two by quite a lot. The EQ Plus, compressor and downward expander do more to transform your audio than almost anything else you can do. The bass and treble frequencies chosen on it are perfect center and width and Q for voice.
Julius did an outstanding job with taking sensible 'middle' ground averages for all the control points making this equipment FAR easier to set up than actual pro-audio rack equipment for the average Joe.
I prefer the flexibility of rack equipment myself, but I had a full time career as a sound engineer so the configuration of all the interconnects, grounding and proper attenuation into my rigs is not something I had any confusion with.
With Julius' equipment, it is FAR simpler to get things done right without that background and it's easily 9/10's or better the equivalent of budget rack equipment.
I still run his iPlus as my multi-rig interface for my single PTT switch and mic as well.
As for SSB vs FM/AM, one trick if you buy both pieces is to set up for flat, natural response without the 8-band turned on, for AM and FM use. Then for SSB, set up the EQ on the 8-band to drop the mids a bit, boost the bottom and highs. All you have to do is then flip the 'on' switch on the 8-band when you do SSB and flip it off on AM and FM.
One last parting shot. With EQ, often what you want to achieve, more highs, more bottom, can be achieved by dropping something else out of the way. If mids are too hot, it will sound like you need to boost the bass...instead, try dropping out your mids. If you feel like you need more articulation, try dropping somewhere between 160-400Hz out. If you sound boxy, look at 500-800Hz depending on your voice.
After dropping wth an EQ, it is attenuating the overall level many times, so to recover the 'volume' level, you do that with the output level after your changes.
It is _always_ the best and cleanest audio if you drop out with an EQ vs boosting. You can't always get what you want this way, but DO try it first.