When testing Napalm Grenade's vNG variations I found that the switch from BLights to Gemfinders had mixed results. I was expecting a more serious increase in speed, but in the end it became barely noticeable. I would expect the same trend here: It's faster but only slightly.
On the subject of Dragons, I recall discussions about this deck taking place where the difference in speed of Crimsons versus Rubies was noted. Crimsons managed to improve the speed.
But.
In saying that, I have noticed cases where upped Dragons actually made a deck faster even though there seems to be a consensus that Unupped Dragons = more speed.
I'd like to see more tests done on Crimsons versus Rubies in this deck to get a better idea of exactly what is faster and why this is the case. I would then also like to see exactly what is required for unupped Dragons to increase the speed of other decks as well.