Short answer: No. The Kyosho car is a much higher quality.
Long answer: Maybe. Depends. KInds of. You CAN race the ECX car. I raced my Boost buggy and AMP/Circuit. They couldn't keep up with the other cars on the track in terms of handling (on a high-traction surface like astro or carpet as the ECX cars are optimal for dirt) but I learned a lot by tuning the cars as best I could. When I bought a TLR 22 3.0 buggy it was a night-and-day difference.
The ECX Boost buggy is what I started with. The Boost is very similar to the AMP cars but it has a narrower track width and slightly shorter wheelbase (because it's a buggy). Then I got an AMP MT and converted it to a Circuit (only change was the rear shock tower. The AMP cars use the Boost rear shock tower and the Circuit rear shock tower has different body mount positions (I also bought a Circuit body) and slightly changes the top position of the shocks.
But neither of those changes is absolutely necessary. Just get tires appropriate for the track surface and you'll be 90% there!