I do, especially if I rush them to max level early, taking Bulwark and then finally Sacrifice. These two abilities, along with Aid Protocol from a specialist, makes the Berserker Queen and Aarchon King encounters a cakewalk. They have a hard time hitting, and if they do they do about 3 damage thanks to all the armor.

They also laugh at the Chosen. The Chosen rely on their debuffs which Sparks are completely immune to and can take advantage of several Chosen weakness (Bewilderment, Brittle, Grounding, and whatever makes them take extra damage from explosives). Nothing is funnier than a Spark finishing off a Chosen by punching them.

With a superior scope for aim and expanded magazine they can reliably hit anyone in low cover and do 3 attacks in a row. Plus Rainmaker + Plasma Blaster means you severely injure an entire pod. Or two.

They are my favorite units. I try to have two, one specced to be a tank and one specced to be all offense oriented.