I am looking all over not seeing much on that thing its only been shipping a month and a half from the looks of it though. Good luck finding info along with parts. X
the mugen st-1 looks like the losi xxx-nt. well, sort of. i saw one on the internet at r&l hobbies. $474. in my opinion, i'll stick with the losi xxx-nt for $135 less.
I have one, they are indeed very similar to the xxx-nt
They handle great right out of the box, I'm running Chad Bradleys set up.
You'll need a couple upgrades if you get an older kit
1st
you want the aluminum rear up rights, the plastic ones are okay but they were and get sloppy very quickily (told they will be coming in newer kits)
2nd,
make sure you get the black rear axles, the silver ones are pron to breaking,(also in the newer kits)
3rd.
get the aluminum rear hubs, the plastic ones let the axle move around to much and that will make it more likely to break. the aluminum ones stiffen the axle/hub/wheel conection.
Look around on ebay, I bought mine with the mt12 for $330,