It just depends on your situation. If you CAN wait to get what you want, you're better off doing it in the long run. If you NEED something sooner, well, maybe you have difference choices.
In my case, I waited as long as I could. After five months (July 26-Dec 28) and they still could not give me any kind of ETA at all, I just had to cancel the order and move on. I couldn't wait anymore, I was desperate for a replacement vehicle. I could have bought something else in the meantime, and then sold it when and if the Rubcion came along, but honestly, I was not sure that it would EVER get built. I didn't want to get until May or June or whenever they call it quits, only to be told something to the effect of, "well, sorry, we didn't get around to building your car. Try again next year".
So, good luck with your order! (: