From hearing a friend's system as he went through the Scout to Scoutmaster upgrades, you may get more improvement by first upgrading to the 300 rpm motor, then adding the SDS. The folks at VPI can give you some good guidance on this if you call them.
After upgrading to the 300 rpm motor, the further improvement from adding a motor controller will be very noticeable. It's not a component level upgrade improvement, but it's significant enough that you're not likely to be willing to give it up once you've heard the difference.
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After upgrading to the 300 rpm motor, the further improvement from adding a motor controller will be very noticeable. It's not a component level upgrade improvement, but it's significant enough that you're not likely to be willing to give it up once you've heard the difference.
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