ok so, Sparky is interesting, he is best used to end drain which is surprisingly easy to do of your an elec/elec. Just an extra source of -end to keep the bad guys drained which, keep in mind, your build up in elec adds to this a lot. Your primary nuke as well as your short circuit will be your likely DPS hits when you hit it and most bosses are almost drained dry at this point. something interesting to point out is I have sapped as consequence with no investment in it many a enemy that happens to be hard to sap otherwise using kin defenders with electrical blast just because I have one extra -recovery power which refills my own end. Occasionally I will get a couple surviving LT's which the addition of sparky is great at handling, just a 3 slot investment in end mod sets with damage on their enhancements makes it a little added safety net. I haven't tried other blaster pets besides the gun drone and devices bombs but it seems like if this is an indication they are good tools for soloing for their utility before you have a maxed out build.