Originally Posted by bill_delong

1) Ideally you want servo that is over 200oz-in of torque and between .08-.12 sec/60°
2) Radio lacks computer controls, ideally you want a system that includes exponential steering as a bare minimum for a novice driver, this will vastly improve the handling of the car making it easier to drive
3) ESC/motor combo is over powered at 2500kV, plus it's a sensorless system which won't be as smooth when driving in more technical sections of the track, ideally you want a 1900kV motor for optimal efficiency, there is a saying in racing, "slower is faster", you gotta trust me on this, a 1900kV motor will be easier to drive, smoother to clear jumps more consistently and offer 2500/1900 = 32% longer run time
4) Tires that come with RTR's are too hard of a compound, most race tracks will use a soft compound tire for best performance, plus you'll want to punch vented holes in your tires before you mount them, that's a short cut most RTR's lack.

I'm not an expert on the Losi, but in general, most RTR's will cut costs by reducing some upgrades, I would visit your local track and have them go over each item, but at a quick glance from the product pics, this is what I'm seeing on the RTR:
1) Plastic shocks, kit should have aluminum shocks
2) Plastic non-adjustable links, kit should have aluminum turnbuckles... this is VERY important for setup changes
3) Plastic pivot blocks, kit should have all aluminum blocks... this will be a durability concern

RTR = Ready To Reassemble, most RTR's take short cuts in the building process, the assemblers rarely put grease on the rubber seals which are the root cause for leaky diffs and shocks, plus they rarely put the right fluids that you will need for your track conditions anyway. They also fail to use thread lock on any metal to metal fasteners. When you assemble the kit yourself (typically 4-8 hours) you will learn how everything goes together so when a part breaks, you'll easily be able to make quick repairs yourself.

If you're super intimidated and just want to get the RTR, that's cool, but be prepared to have to buy twice and spend a lot more money than if you just bought the kit in the first place. This is one of those things that patience will go a long way in saving you time and frustration later.

Best of luck on your decision, Losi is a solid choice for both durability and performance.

If you need help selecting low budget electronics,middle of the road, or the highest quality, let me know and I can make some more suggestions for you to consider.