The Intel Cherry Trail X7-Z8750 is actually a performance chipset of the Atom Family. The last X5-Z8300 was a budget or Mainstream Chip. And in terms of performance, you can refer below for charts and test from Teclast.
The graph above is from Teclast, and it shows performance boost is now comparable to the performance of the Intel Core M Chipset. Although it is slower compared to the Intel Core M3 Chipset because on Cinebench, it usually gets around 195 to 210 Cinebench scores.
The new Intel Graphics 405 is also more capable in terms of gaming. In comparison, the X5-Z8300 was really slow in gaming and I do not recommend it. However, the newer GPU seems to hold great expectations. According to Teclast, it can easily reach stable framerates and above 30 fps. You can refer above.