Well to be honest they are a bit hard to compare as spark is a drum synthesizer and maschine being more of a sampler/midi controller/ sequencer.
Maschine does have a lot more functions. in terms of a central workstation as well it is pretty decent for hip hop beat makers.That being said, if you are into electronic music like me, maschine is too basic in terms of beat making and the interface is not that fun to use. The reason I say spark is brilliant is because it is a drum Synthesizer allowing you to find your kicks, hats, snares etc and tweak them to your liking, the basic foundation in your setup to start with beats. It also has a decent touch effects pad. Basically using the spark plugin inside Ableton( thats what I use) is brilliant, my foundation of the track is built around the spark drum kit and my other sounds would be derived from plugin synths.
The perfect setup would be the arturia spark
with the virus ti(my dream synth) and thats the best combination for electronic music right there. Two beasts of sound to have your setup around to make an easy workflow.
Again this is just my opinion, as that would be a smooth workflow for me. I may not find the maschine so good because I use Ableton and when I try running the maschine as a plugin through ableton it does not sit over so smooth. I just end up making pointless beats for hours on end ( its fun but not really productive)