i just ordered the new rMBP with the 370X. How was the performance for 750M users using a 4k display? I take it any sort of gaming on it is impossible? I'm contemplating which monitor I want to buy and I feel that if I don't go 4k, I'll regret it. Granted, I won't do hard core gaming on it but if it's a horrible experience, I don't want to do it. Another option I was considering was going the eGPU route with a GTX970 but I've been hesitant to think of that as the costs associated with getting it up is quite costly and I figure I might as well build a windows/hackintosh for that price. So, monitor suggestions?