I chose the SpectraDrive over the similarly priced EHX Battalion because I liked the idea of TC's 3-band SpectraComp compressor. However, I was very disappointed with the unit. The default compression and overdrive are fairly useless. Also, you can't use the compressor without also engaging the full preamp section. Neither can you use the drive alone. The Battalion allows both to be used independently of the preamp tone controls.
The other issue, and the reason I had to return the unit, was the the TonePrint system simply did not work. The unit refused to accept new patches either from my phone or my computer. This just made me realize that I don't want a digital unit. Too many complications.
I decided to instead buy the Ampeg OptiComp and a TC MojoMojo overdrive, both of which are analog. I already have a SansAmp. But I also tried the Battalion at a local store and it sounds nice and is all analog. If I wanted the EQ section or DI, I would buy it.