RE: what brand produces best quality.
Saint is completely true, not having parts at your LHS will put you down for a few days unless you want to pay for ridiculous overnight fees. Losi is usually found in most LHS as well as Traxxas and HPI. The rest of the brands are hit or miss Team associated seems to be in a lot of LHS around Baton Rouge but not in my hometown in FL.
Now as far as those 3 I said the Xray. I have heard that no car, truck, buggy, truggy or what have you goes together like an Xray. The parts fit together like they are precision cut. Im not 100% sure on the weight of the Xray but i do know that the Mugen has a rediculous amount of CF on it and is super light.
Odonells to me seems to be new on the market, everything i have heard about that buggy seems to be good, but i havnt heard alot.