I think the exaggeration on speedo cost is making this look more meaningful than it is. Really we are talking about a $55 or $60 speedo compared to a $95 speedo. If you have to add a lipo cutoff unit then people replacing their speedo are really spending about the same money.
We are all for the box stock Slash class and think it has been great for the hobby. However as time goes on and more of these are available used it also makes sense to allow more choices. Brushed speedos have not gotten any faster in the last decade, just smaller and more features. So a $15 ebay speedo, a rtr replacement or a current racing speedo that could also be used in other cars are all equal choices when it comes to performance in a car like this.
Yes a hi end radio can be a significant advantage because you can dial in things like drag brake, brake strength, steering response and low end throttle curves to control wheel spin.
Smarter, Smaller, Faster....