I purchased the Spark scooter for my son's 6th birthday. He did request it and I tried to sway him as he already had a razor scooter. I gave in justifying the other was old.
I'm glad I made the purchase. It is a nice redesign of the original. It has a wider deck and he can stand and balance on it better. Plus it just looks cool (important for a 6 year old!).
The only downside is the spark cartridge wears out quickly. It does come with one spare but it would cost a small fortune to keep the sparks flying.