I t is amazing how many people have different reactions and opinions to cars. I have heard alot of people saying the XRAY has the best fit and Finish, so when I said before that the Serpent requires fit and finish I may have not been fully clear.
The overall build of the 720 is fantastic, the fit and finish throughout is impeccable. The only areas that require fit and finish is the movement of suspension specifically the rear end, brand new out of the box it is really tight. You have to take the time and polish the ball ends for the rear sway bar so it moves completely free and does not affect the suspension, Also making sure the pivot ball suspension moves freely at all angles front and rear, but these are things most experienced drivers will work on feveoursly if its a 720 or XRAY or Mugen or Kyosho, which is another chassis not mentioned here, which in right should be because its a fantastic car.
Im not trying to stick up for the serpent because really I think all chassis are amazing and will do the job, I dont think there is a clear winner or chassis that is better then the other. It really comes down to preference, who knows maybe its the way the box looks or if it says luxury RC car or Race Prooven design etc.. I know guys that swear by Mugen and think everything else is crap, or people who swear by Kyosho and think everything else is crap.
The real answer here to the best car or vs. is the more time you spend with a car because the more you know it and feel comfortable working on it, I can basically build a 720 from new in less then 2hrs and it would be in full race spec, but thats because I have been working on it for 3 years.
One of our local racers had been driving the Kyosho for a year, wen to the Serpent didnt like it, went back to the Kyosho, bought the Mugen, didnt like it, went back to the Kyosho, bought the NT1 didnt like it and went back to the Kyosho, because he understood the car and was able to work on it. My best advice is to Pick a car you feel most comfortable with and in lack of better words commit to it. Because it takes alot of time to understand each car, what setups to put on it for different tracks and or conditions the best tires etc.. Its been 3 years and I am still learning things that make my car faster. Any chassis Mugen, Kyosho, XRAY, Serpent, Team Magic, Heck HPI. With the right amount of time testing practising will all yield you results..
.k maybe not the HPI 
Anyways my two cents