I can immediately see one issue that you will have. The X-axis belt needs to be parallel to the movement of the axis where it attaches to the carriage. Otherwise the effective length of the belt changes as you move the axis from one side to the other, your belt tension will change, and you will have printing inaccuracies. To check this, move your X axis to the middle and test the belt tension. Then move it to one side. You will see the tension change.
Other than that it looks quite nice. My MendelMax is quite over-sized, which results in significantly reduced maximum print and travel speeds. My maximum comfortable travel speed is 130mm/s, and max reasonable print speed is about 70mm/s.
