The ME 8B is a fantastic unit, I bought one in 1997 and I still use it.
The compressor is nice, you can go from a subtle compression to a very compressed tone. The controls are note very intuitive but once you understand them it's quite easy to set up.
I like the octaver, it has the same limitation that all analog octavers have: you can't play chords or doublestops. That said is a very decent octaver.
There as 5 distortions to choose from, you get the bass over drive and some other classic guitar pedals such as the Metal Zone and Fuzz. They all offer a direct level control so you can blend the distorted sound with the clean sound. This opens lot's of possibilities and it is not a very common feature.
The EQ allows you some serious tone shaping. 'nuff said!
I believe this was the first bass unit to include the Synth Bass. There are 9 synth sounds and an auto-wha. Some of the Synh sounds use an internal generator, so the unit identifies the note you're playing and plays a Synth note, with the possibility of using a sustain pedal to hold the note, very cool. There are some synth sounds that are just your bass processed, and there is the auto- wha that get you some serious funky tones.
The chorus effect has a nice low filter, so you can choose if the chorus will alter all your notes or just the higher register. This is a very nice thing so the low end doesn't get messy and muddy but you can have that nice chorus in the upper register without having to switch on and off all the time. The flanger is also good, both can be used mono or stereo.
The delay is very nice, you can set it mono or stereo and choose between setting the tempo or counting it in. I would love to be able to use the ctrl pedal to mute the Delay input so I could use it as a sampler unit but, hey, it is a 13 years old pedalboard
You have a nice reverb, nothing special.
There is a "control" pedal that allows you to switch one effect on and off, count in the delay, hold the synth sound and some other things. The wha option is cool but has a weird tone, I wish the wha would not color the sound when I'm not stepping in the control pedal, but that's ok.
I've never used the optional expression pedal so I can't comment on that.
The unit is very quite, it has a noise suppressor that avoids unwanted noises specially when using distortion. I can't comment on the factory pressets because they are long gone. As I said, my ME 8B was bought in '97, I've been using since then and I had virtually no problems. I have stomped on the pedal over and over and they don't show signs of wear.
The tone is incredible and the adjustments Boss made to the distortion and chorus makes it a very hard o replace unit. I honestly don't know if the new units have the low filter in the chorus and the direct volume on the distortion.
