Both cars are great cars it just depends on how much money you want to spend. To be honest its up to you, asking a question like that on this site will only get people like XXXKAT who is a complete dumb a$$ in the first place, saying this car sucks and this car is great. Every car has its pluses and minuses. Yes the MI2 does have its hang ups but it also has all of good things. I have been running the stock shocks that come with the car and they have been just fine. They are pain to put together but once they are put together they are just fine. I really cant give you a good review on the tamiya car because I have never run one but from what I can see at the track running against them they are a very good car also and I am sure they have there hang ups also I would recommend asking a team driver or someone at your track that has the car. Just do your home work before making a big investment.
And yes xxxkat I called you a dumb a$$ you come on these threads and make such stupid comments and you wonder why no one wants to help you out with setups or anything else. Do use all a favor and sell all your r/c stuff and take up another hobby like fishing or something so you can get on there web sites and be a pain in there a$$ for a while. I am sorry I have better manners than that. PLEASEEEEEE!!!!