Today I spoke with Blade from RGX Racing for over an hour. His company is a couple miles away from Cen's main offices and distribution center. He explained to me that there are currently three versions of the TR Arena available through him. First there is the Factory Race Edition (FRE) which you can check out on Cen's website. Second is the Almost Ready to Run (ARR), it comes assembled with identical parts used in the RTR kit. The only difference between the RTR and the ARR kit is that the ARR kit has the blue lightweight hubs and no factory radio. Servos are included in the ARR, so those who have aftermarket radios may be intrested in this package. The lightweight hubs cost around 60 dollars. Cen will be releasing a milled lightweight chassis upgrade for all three versions of the Arena truggy, so look out for that. His prices are higher than other companies that sells the TR Arena online, but that's because he deals directly with Cen and is a Authorized Cen dealer. So when you buy a Cen product from him the warranty does apply. RGX Racing also throws in a couple of handy coupons and stickers to offset the slightly higher price of their Cen products.
Check out this website
http://www.rgxracing.com/ for more info.