Well to answer your question quite bluntly... yes they have an advantage.
In my opinion it will be possible for a less proficient driver (with the new technology esc) to keep up with a better driver using an older esc (without the electronic trickery). These days you need to be as good with the laptop as you are with driving and setup.
I was quite happy using Novak gtb's in all of my cars/trucks for years, never had one problem with any of them, hell, I even use some of them still (the originals w/o the internal lipo cut off. they are workhorses real clydesdales
. but after reading about the "new breed" of speedo's I got a Tekin RS Pro, Wow, they were right, there is a big difference in the way you can get the power if you know how to do it. The main advantage in spec racing in my opinion is the timing you can get out of the speedo even if the motor timing is fixed(non adjustable).
Losi 8ight brushless, Losi xxxt-cr, Losi jrxs type R, Losi street weapon,
Rc10T1 rebuilt, Rc10 "worlds" .Xray T2, Atlas YM-34, Losi XX pro SE
TRC Predator Lynx 2. Tenth Technology super touring, Predator X-10, X-11.
Losi Micro-T, Losi Mini-T, Rc18T, Xray M18
Schumacher Fireblade Evo. All Electric