I think it depends if you want to really understand how your car works, for example i had a Rush Evo for my first car and yes i kinda understood it but because it came built i just started running it whereas with the savage i know exactly which bit does what, how it goes in etc becuase i put it there. Theres a difference between getting a rtr and running it becuase nearly anyone can do that, whereas not everyone can say yeah u built that from a box of parts.
If i was gonna next buy a nitro it would be rtr but it would no way be as big as savage because it took me a good 12hours, i would like something like a hellfire, something thats not really as big. I used to take my savage to bits all the time after i built it, just when i got bored but now i just many run it and don't bother taking it to bits, don't think theres much point unless u know that you need to make sure something has not broke etc.