Hi Johnny, I have several Scorpion Motors in various planes, I think that they are decent motors. You can find motors for less money, but you usually get what you pay for.
The Scorpion Sll-3020-890 is comparable to the E-flite Power 15 BL. The Scorpion is $10.00 less in price. I like the prop data that is available for the Scorpion motors as well as the voltage charts. I also have E-Flite motors in various planes and I think that they are OK motors as well.
So it's really the modeler's choice as to what they want to invest in their system. I don't think that you will go wrong if you buy a motor,esc,or battery that has good reviews from the people on this forum that are using them. Here's the website that you can check out for information about Scorpion motors, if you don't already have it.