So I went downstairs and messed around for 10 minutes so that I could give you a slightly better response...
Look - I don't have every kind of fuzz pedal: I have Muffs, one Tonebender, one Shin Ei type (the Sasori), one that has been compared to a Wooly Mammoth (the FATM), one fuzz face type that I never use on bass (the Keeley Fuzz Head) and I have the Spaceman types. Then the Duality which is clearly its own beast. I don't have anything like a Bee Ba or the B:Assmaster. So I can't compare there.
The Spaceman fuzzes I have don't really sound so much like another type of fuzz that you would immediately say "IT'S A TONEBENDER" or whatever. They are rather unique. The two I have are very different but they do share a particular "Spaceman" flavor.
The Spacerocket has a three position switch on top. Tthe switch controls fuzz gain in theory but it feels like it is adding mids. I like the first position (most bass) and third position (best cut) the most. Maybe the gain is mid-range focused?
It's not a creamy type of Muff fuzz at all, but it retains low end really well on all settings. You notice the lows more in the first setting maybe because there is less going on to distract you from them. When you pay attention, low end definition is solid on each setting.
I would generally describe it as having a pretty cutting (dare I saw buzz saw) style to it. But nothing as extreme or as horn like as the Sasori - that REALLY excels in this regard. But it is richer than the Sasori - partially because it has a crushing low end that you can feel and partially because the tonal nature is just different.
That was about as helpful as a hernia, I know.
I feel like it has the low end of a good Muff and the cut/bite of a good buzz saw. With a midrange that is variable as you move the switch.
I hadn't realized that Zach still had Spacerockets in stock. I do sometimes I wish I had sprung for one of the style-y-er finishes like the Chrome or brushed silver. I also didn't realize that the Spacerockets were that expensive at manufacturer's retail. I got mine at a great price and frankly I didn't even realize it. I thought they were around $225 new (in the basic finish).
To be honest, at the prices on the site, I would cough up the extra and get a Sputnik. Of course, springing nearly 4 bills for a fuzz isn't on everybody's happy-happy-joy-joy list. It isn't on mine for sure. But I am super happy I bought a Sputnik.
And to think @DirtyDuke tells me that the Gemini III is even more versatile.
Speaking of which, Duke or @nshuman - anything to add?
This is the Sputnik that I really like - finish wise -
Spaceman Sputnik 23 of 35 | Reverb There is an olive one on Reverb as well - which is also quite nice
Spaceman Sputnik Germanium Fuzz #24 of 50 | Reverb
I have the jack waiting here.
Took the tuner off to make place for the fuzz. There's still some room but I need a bigger board and 2nd psu to fit my tuner, filter, looper, Valvedrive and Tonehammer. Looking forward to my upcoming gigs to roadtest the new fuzz. 
