i had the same question 2 months ago..
but it was an easy decision. I had an AE TC6.1 worlds that i got for 360 shipped, had it for 4 months and was a great car to learn from. I was not even selling it but i found a TRF417v5 for 480 shipped. Sold my TC6.1 on ebay and bid went up to $330.00 surprisingly. so for an extra 150 bucks i got me a TRF
TRF417v5 - $480 shipped which used to be a $750 car (last year)
TRF418 - $750 or more because its the newest
not sure if the performance is worth the extra 300 bucks. Besides there is a new car every friken year... Am i gonna buy every new TRF that comes out?? Hell NO!
I have guys in my local race track that drive a yokomo from 2005 and old hpi pro 4's and smoke guys that have newest chassis...
you can have the best car out, you still gotta drive it... lol
However, my observation has been that a good amount of people always buy the most current a latest kit... to each their own i know that is when the hobby becomes out of control for such miniscule result and not guaranteed positive results.
a 418 is a $750 car which will eventually become a $480 car when the new 418x 418_ comes out.... question is are you willing to keep changing cars every year?? its like man... how do you keep up when new stuff comes out yearly... I just focus on how to get better in driving.
for me i am extremely satisfied with my TRF417v5 and will have it for about 2-3 years and call it good maybe even longer.
I take such good care of my stuff that it might still look new 3 years from now. lol.
Besides im kinda new and not the best driver yet so i didnt see the point of spending $750.00
Hope this helps
Good luck SIR!